An intimate interaction between a pair of amino acids, a tyrosine and glycine on neighboring β-strands, has been previously reported to be important for the structural stability of autotransporters. ...Here, we show that the conservation of this interacting pair extends to nearly all major families of outer membrane β-barrel proteins, which are thought to have originated through duplication events involving an ancestral ββ hairpin. We analyzed the function of this motif using the prototypical outer membrane protein OmpX. Stopped-flow fluorescence shows that two folding processes occur in the millisecond time regime, the rates of which are reduced in the tyrosine mutant. Folding assays further demonstrate a reduction in the yield of folded protein for the mutant compared to the wild-type, as well as a reduction in thermal stability. Taken together, our data support the idea of an evolutionarily conserved 'folding core' that affects the folding, membrane insertion, and thermal stability of outer membrane protein β-barrels.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The Sunbelt Melanoma Trial is a prospective randomized trial evaluating the role of high-dose interferon alfa-2b therapy (HDI) or completion lymph node dissection (CLND) for patients with melanoma ...staged by sentinel lymph node (SLN) biopsy.
Patients were eligible if they were age 18 to 70 years with primary cutaneous melanoma ≥ 1.0 mm Breslow thickness and underwent SLN biopsy. In Protocol A, patients with a single tumor-positive lymph node after SLN biopsy underwent CLND and were randomly assigned to observation versus HDI. In Protocol B, patients with tumor-negative SLN by standard histopathology and immunohistochemistry underwent molecular staging by reverse transcriptase polymerase chain reaction (RT-PCR). Patients positive by RT-PCR were randomly assigned to observation versus CLND versus CLND+HDI. Primary end points were disease-free survival (DFS) and overall survival (OS).
In the Protocol A intention-to-treat analysis, there were no significant differences in DFS (hazard ratio, 0.82; P = .45) or OS (hazard ratio, 1.10; P = .68) for patients randomly assigned to HDI versus observation. In the Protocol B intention-to-treat analysis, there were no significant differences in overall DFS (P = .069) or OS (P = .77) across the three randomized treatment arms. Similarly, efficacy analysis (excluding patients who did not receive the assigned treatment) did not demonstrate significant differences in DFS or OS in Protocol A or Protocol B. Median follow-up time was 71 months.
No survival benefit for adjuvant HDI in patients with a single positive SLN was found. Among patients with tumor-negative SLN by conventional pathology but with melanoma detected in the SLN by RT-PCR, there was no OS benefit for CLND or CLND+HDI.
The Chilean Sepedonium aff. chalcipori strain KSH 883, isolated from the endemic Boletus loyo Philippi, was studied in a polythetic approach based on chemical, molecular, and biological data. A ...taxonomic study of the strain using molecular data of the ITS, EF1-α, and RPB2 barcoding genes confirmed the position of the isolated strain within the S. chalcipori clade, but also suggested the separation of this clade into three different species. Two new linear 15-residue peptaibols, named chilenopeptins A (1) and B (2), together with the known peptaibols tylopeptins A (3) and B (4) were isolated from the semisolid culture of strain KSH 883. The structures of 1 and 2 were elucidated on the basis of HRESIMS n experiments in conjunction with comprehensive 1D and 2D NMR analysis. Thus, the sequence of chilenopeptin A (1) was identified as Ac-Aib1-Ser2- Trp 3 -Aib4-Pro5-Leu6-Aib7-Aib8-Gln9-Aib10-Aib11-Gln12-Aib13-Leu14-Pheol15, while chilenopeptin B (2) differs from 1 by the replacement of Trp3 by Phe3. Additionally, the total synthesis of 1 and 2 was accomplished by a solid-phase approach, confirming the absolute configuration of all chiral amino acids as l. Both the chilenopeptins (1 and 2) and tylopeptins (3 and 4) were evaluated for their potential to inhibit the growth of phytopathogenic organisms.
DNA can enter the blood circulation from living cells by extracellular vesicles or at cell death, and pass into urine through the kidney barrier. Urine can be collected non-invasively, making it an ...interesting source of cell-free DNA (cfDNA) for research studies and ultimately for clinical diagnostics. However, there is currently a lack of data on the quantity and variability of cfDNA in urine. Here, we benchmark two commercial urine cfDNA isolation kits with respect to the quantity of DNA, the labor time, and cost. The results show distinctive differences between each kit. Furthermore, the cfDNA amount from the same probands varied strongly from day to day and may be higher in female samples than in male samples (p = 0.003).
Osteoarthritis (OA) is the most prevalent joint disorder, causing pain and disability predominantly in the aging population but also affecting young individuals. Current treatments are limited to use ...of anti-inflammatory drugs to alleviate symptoms or degenerated joint replacement by a prosthetic implant at the end stage of the disease. We hypothesized that degenerative cartilage defects can be treated using nasal chondrocyte–based tissue-engineered cartilage (N-TEC). We demonstrate that N-TEC maintained cartilaginous properties when exposed in vitro to inflammatory stimuli found in osteoarthritic joints and favorably altered the inflammatory profile of cells from osteoarthritic joints. These effects were at least partially mediated by down-regulation of the WNT (wingless/integrated) signaling pathway through sFRP1 (secreted frizzled-related protein-1). We further report that N-TEC survive and engraft in vivo in ectopic mouse models reproducing a human osteochondral OA tissue environment, as well as in sheep articular cartilage defects that mimic degenerative settings. Last, we tested the safety of autologous N-TEC for the treatment of osteoarthritic cartilage defects in the knees of two patients with advanced OA (Kellgren and Lawrence grades 3 and 4) who were otherwise considered for unicondylar knee arthroplasty. No adverse reactions were recorded, and patients reported reduced pain as well as improved joint function and life quality 14 months after surgery. Together, our findings indicate that N-TEC can directly contribute to cartilage repair in osteoarthritic joints. A suitably powered clinical trial is now required to assess its efficacy in the treatment of patients with OA.
The DEAD-box RNA helicase eIF4A, which is part of the heterotrimeric translation initiation complex in eukaryotes, is an important novel drug target in cancer research because its helicase activity ...is required to unwind extended and highly structured 5′-UTRs of several proto-oncogenes. Silvestrol, a natural compound isolated from the plant Aglaia foveolata, is a highly efficient, non-toxic and specific inhibitor of eIF4A. Importantly, 5′-capped viral mRNAs often contain structured 5′-UTRs as well, which may suggest a dependence on eIF4A for their translation by the host protein synthesis machinery. In view of the recent Ebola virus (EBOV) outbreak in West Africa, the identification of potent antiviral compounds is urgently required. Since Ebola mRNAs are 5′-capped and harbor RNA secondary structures in their extended 5′-UTRs, we initiated a BSL4 study to analyze silvestrol in EBOV-infected Huh-7 cells and in primary human macrophages for its antiviral activity. We observed that silvestrol inhibits EBOV infection at low nanomolar concentrations, as inferred from large reductions of viral titers. This correlated with an almost complete disappearance of EBOV proteins, comparable in effect to the translational shutdown of expression of the proto-oncoprotein PIM1, a cellular kinase known to be affected by silvestrol. Effective silvestrol concentrations were non-toxic in the tested cell systems. Thus, silvestrol appears to be a promising first-line drug for the treatment of acute EBOV and possibly other viral infections.
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•The rocaglate silvestrol, a specific eIF4A helicase inhibitor, is a potent antiviral compound to treat Ebola infections.•Silvestrol inhibits EBOV in human primary macrophages at low nanomolar concentrations.•Silvestrol is not toxic in vitro and in vivo at concentrations of effective antiviral activity.•Inhibition of cap-dependent translation initiation is a potent antiviral strategy.
Owing to the kinetic nature of the glass transition, the ability to significantly alter the properties of amorphous solids by the typical routes to the vitreous state is restricted. For instance, an ...order of magnitude change in the cooling rate merely modifies the value of the glass transition temperature (T(g)) by a few degrees. Here we show that matrix-assisted pulsed laser evaporation (MAPLE) can be used to form ultrastable and nanostructured glassy polymer films which, relative to the standard poly(methyl methacrylate) glass formed on cooling at standard rates, are 40% less dense, have a 40 K higher T(g), and exhibit a two orders of magnitude enhancement in kinetic stability at high temperatures. The unique set of properties of MAPLE-deposited glasses may make them attractive in technologies where weight and stability are central design issues.
Background Wet-wrap treatment (WWT) has been advocated as a relatively effective treatment in children with severe atopic dermatitis (AD). WWT often serves as crisis intervention for AD. Objectives ...We sought to evaluate the use of WWT with diluted corticosteroids in comparison with emollient in children with severe AD during 4 weeks in a proactive schedule during which the frequency of corticosteroid applications was tapered. Methods A randomized, double-blind, placebo-controlled study was performed in children aged 6 months to 10 years with severe AD (objective SCORAD at least 40 ± 5), comparing WWT with diluted corticosteroids (1:3 mometasone furoate 0.1% ointment and for the face 1:19 mometasone furoate 0.1% ointment under a mask) with emollient (petrolatum 20% in cetomacrogol cream). The primary outcome was improvement of the objective SCORAD; secondary outcomes included Patient-Oriented Eczema Measure and quality-of-life index. Results WWT with diluted corticosteroids acted faster and was more efficacious than WWT with emollients. Best results were obtained in age groups 6 to 9 years and 0 to 3 years. The difference in efficacy evaluated by objective SCORAD was significant at all measuring points. This also applied to the quality-of-life index. Limitations The study group was relatively small. Conclusions WWT for severe AD is an effective therapy option for at least a period of 4 weeks.
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