scholarly journals Nanofiber-Mâché Hollow Ball Mimicking the Three-Dimensional Structure of a Cyst

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2273
Author(s):  
Wan-Ying Huang ◽  
Norichika Hashimoto ◽  
Ryuhei Kitai ◽  
Shin-ichiro Suye ◽  
Satoshi Fujita
Keyword(s):  
Three Dimensional ◽  
Hollow Structure ◽  
Dimensional Structure ◽  
The Novel ◽  
Fibrous Scaffold ◽  
Hydrogel Beads ◽  
Inner Surface ◽  
Intracranial Epidermoid ◽  
Hollow Ball

The occasional malignant transformation of intracranial epidermoid cysts into squamous cell carcinomas remains poorly understood; the development of an in vitro cyst model is urgently needed. For this purpose, we designed a hollow nanofiber sphere, the “nanofiber-mâché ball.” This hollow structure was fabricated by electrospinning nanofiber onto alginate hydrogel beads followed by dissolving the beads. A ball with approximately 230 mm3 inner volume provided a fibrous geometry mimicking the topography of the extracellular matrix. Two ducts located on opposite sides provided a route to exchange nutrients and waste. This resulted in a concentration gradient that induced oriented migration, in which seeded cells adhered randomly to the inner surface, formed a highly oriented structure, and then secreted a dense web of collagen fibrils. Circumferentially aligned fibers on the internal interface between the duct and hollow ball inhibited cells from migrating out of the interior, similar to a fish bottle trap. This structure helped to form an adepithelial layer on the inner surface. The novel nanofiber-mâché technique, using a millimeter-sized hollow fibrous scaffold, is excellently suited to investigating cyst physiology.

scholarly journals Efficacy of Novel Hemagglutinin-Neuraminidase Inhibitors BCX 2798 and BCX 2855 against Human Parainfluenza Viruses In Vitro and In Vivo

2004 ◽  
Vol 48 (5) ◽  
pp. 1495-1502 ◽  
Author(s):  
Irina V. Alymova ◽  
Garry Taylor ◽  
Toru Takimoto ◽  
Tsu-Hsing Lin ◽  
Pooran Chand ◽  
...  
Keyword(s):  
Sendai Virus ◽  
Three Dimensional ◽  
Parainfluenza Virus ◽  
Dimensional Structure ◽  
The Novel ◽  
Virus Infections ◽  
Parainfluenza Viruses ◽  
Human Parainfluenza Viruses

ABSTRACT Human parainfluenza viruses are important respiratory tract pathogens, especially of children. However, no vaccines or specific therapies for infections caused by these viruses are currently available. In the present study we characterized the efficacy of the novel parainfluenza virus inhibitors BCX 2798 and BCX 2855, which were designed based on the three-dimensional structure of the hemagglutinin-neuraminidase (HN) protein. The compounds were highly effective in inhibiting hemagglutinin (HA) and neuraminidase (NA) activities and the growth of hPIV-1, hPIV-2, and hPIV-3 in LLC-MK2 cells. The concentrations required to reduce the activity to 50% of that of a control ranged from 0.1 to 6.0 μM in HA inhibition assays and from 0.02 to 20 μM in NA inhibition assays. The concentrations required to inhibit virus replication to 50% of the level of the control ranged from 0.7 to 11.5 μM. BCX 2798 and BCX 2855 were inactive against influenza virus HA and NA and bacterial NA. In mice infected with a recombinant Sendai virus whose HN gene was replaced with that of hPIV-1 [rSV(hHN)], intranasal administration of BCX 2798 (10 mg/kg per day) and of BCX 2855 (50 mg/kg per day) 4 h before the start of infection resulted in a significant reduction in titers of virus in the lungs and protection from death. Treatment beginning 24 h after the start of infection did not prevent death. Together, our results indicate that BCX 2798 and BCX 2855 are effective inhibitors of parainfluenza virus HN and may limit parainfluenza virus infections in humans.

scholarly journals Hydrothermal Synthesis and Structural Investigation of a Crystalline Uranyl Borosilicate

Inorganics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 25
Author(s):  
Kristen A. Pace ◽  
Vladislav V. Klepov ◽  
Mark D. Smith ◽  
Travis Williams ◽  
Gregory Morrison ◽  
...  
Keyword(s):  
Synthesis Method ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Exploratory Research ◽  
The Novel ◽  
Orthorhombic Space Group ◽  
Crystalline Materials ◽  
Waste Remediation ◽  
And Storage ◽  
X Ray Absorption

The relevance of multidimensional and porous crystalline materials to nuclear waste remediation and storage applications has motivated exploratory research focused on materials discovery of compounds, such as actinide mixed-oxoanion phases, which exhibit rich structural chemistry. The novel phase K1.8Na1.2[(UO2)BSi4O12] has been synthesized using hydrothermal methods, representing the first example of a uranyl borosilicate. The three-dimensional structure crystallizes in the orthorhombic space group Cmce with lattice parameters a = 15.5471(19) Å, b = 14.3403(17) Å, c = 11.7315(15) Å, and V = 2615.5(6) Å3, and is composed of UO6 octahedra linked by [BSi4O12]5− chains to form a [(UO2)BSi4O12]3− framework. The synthesis method, structure, results of Raman, IR, and X-ray absorption spectroscopy, and thermal stability are discussed.

scholarly journals Protein Folding: Search for Basic Physical Models

2003 ◽  
Vol 3 ◽  
pp. 623-635 ◽  
Author(s):  
Ivan Y. Torshin ◽  
Robert W. Harrison
Keyword(s):  
Protein Folding ◽  
Tertiary Structure ◽  
Three Dimensional ◽  
Physical Models ◽  
Dimensional Structure ◽  
Computational Techniques ◽  
Linear Sequence ◽  
Physical Forces

How a unique three-dimensional structure is rapidly formed from the linear sequence of a polypeptide is one of the important questions in contemporary science. Apart from biological context ofin vivoprotein folding (which has been studied only for a few proteins), the roles of the fundamental physical forces in thein vitrofolding remain largely unstudied. Despite a degree of success in using descriptions based on statistical and/or thermodynamic approaches, few of the current models explicitly include more basic physical forces (such as electrostatics and Van Der Waals forces). Moreover, the present-day models rarely take into account that the protein folding is, essentially, a rapid process that produces a highly specific architecture. This review considers several physical models that may provide more direct links between sequence and tertiary structure in terms of the physical forces. In particular, elaboration of such simple models is likely to produce extremely effective computational techniques with value for modern genomics.

scholarly journals Functional Analysis of the Mycobacterium tuberculosis FAD-Dependent Thymidylate Synthase, ThyX, Reveals New Amino Acid Residues Contributing to an Extended ThyX Motif

2008 ◽  
Vol 190 (6) ◽  
pp. 2056-2064 ◽  
Author(s):  
Jonathan E. Ulmer ◽  
Yap Boum ◽  
Christopher D. Thouvenel ◽  
Hannu Myllykallio ◽  
Carol Hopkins Sibley
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Thymidylate Synthase ◽  
Three Dimensional ◽  
Pyrimidine Ring ◽  
Dimensional Structure ◽  
Directed Mutagenesis ◽  
Catalytic Residue ◽  
Amino Acid Residues ◽  
Insight Into

ABSTRACT A novel FAD-dependent thymidylate synthase, ThyX, is present in a variety of eubacteria and archaea, including the mycobacteria. A short motif found in all thyX genes, RHRX7-8S, has been identified. The three-dimensional structure of the Mycobacterium tuberculosis ThyX enzyme has been solved. Building upon this information, we used directed mutagenesis to produce 67 mutants of the M. tuberculosis thyX gene. Each enzyme was assayed to determine its ability to complement the defect in thymidine biosynthesis in a ΔthyA strain of Escherichia coli. Enzymes from selected strains were then tested in vitro for their ability to catalyze the oxidation of NADPH and the release of a proton from position 5 of the pyrimidine ring of dUMP. The results defined an extended motif of amino acids essential to enzyme activity in M. tuberculosis (Y44X24 H69X25R95HRX7 S105XRYX90R199 [with the underlined histidine acting as the catalytic residue and the underlined serine as the nucleophile]) and provided insight into the ThyX reaction mechanism. ThyX is found in a variety of bacterial pathogens but is absent in humans, which depend upon an unrelated thymidylate synthase, ThyA. Therefore, ThyX is a potential target for development of antibacterial drugs.

scholarly journals Three-dimensional observations of an aperiodic oscillatory gliding motility behaviour in Myxococcus xanthus using confocal interference reflection microscopy

2019 ◽  
Author(s):  
Liam M. Rooney ◽  
Lisa S. Kölln ◽  
Ross Scrimgeour ◽  
William B. Amos ◽  
Paul A. Hoskisson ◽  
...  
Keyword(s):  
Myxococcus Xanthus ◽  
Three Dimensional ◽  
Basal Membrane ◽  
Gliding Motility ◽  
The Novel ◽  
Force Transmission ◽  
Topological Information ◽  
Type Iv ◽  
Microscopy Techniques

The Delta-proteobacterium, Myxococcus xanthus, has been used as a model for bacterial motility and to provide insights of bacterial swarming behaviours. Fluorescence microscopy techniques have shown that various mechanisms are involved in gliding motility, but these have almost entirely been limited to 2D studies and there is currently no understanding of gliding motility in a 3D context. We present here the first use of confocal interference reflection microscopy (IRM) to study gliding bacteria, and we reveal aperiodic oscillatory behaviour with changes in the position of the basal membrane relative to the coverglass on the order of 90 nm in vitro. Firstly, we use a model plano-convex lens specimen to show how topological information can be obtained from the wavelength-dependent interference pattern in IRM. We then use IRM to observe gliding M. xanthus and show that cells undergo previously unobserved changes in their height as they glide. We compare the wild-type with mutants of reduced motility, which also exhibit the same changes in adhesion profile during gliding. We find that the general gliding behaviour is independent of the proton motive force-generating complex, AglRQS, and suggest that the novel behaviour we present here may be a result of recoil and force transmission along the length of the cell body following firing of the Type IV pili.

scholarly journals In Vitro Selection and Characterization of Hepatitis C Virus Serine Protease Variants Resistant to an Active-Site Peptide Inhibitor

2003 ◽  
Vol 77 (6) ◽  
pp. 3669-3679 ◽  
Author(s):  
Caterina Trozzi ◽  
Linda Bartholomew ◽  
Alessandra Ceccacci ◽  
Gabriella Biasiol ◽  
Laura Pacini ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Serine Protease ◽  
In Vitro Selection ◽  
Three Dimensional ◽  
Host Cells ◽  
Dimensional Structure ◽  
In Vitro Systems

ABSTRACT The hepatitis C virus (HCV) serine protease is necessary for viral replication and represents a valid target for developing new therapies for HCV infection. Potent and selective inhibitors of this enzyme have been identified and shown to inhibit HCV replication in tissue culture. The optimization of these inhibitors for clinical development would greatly benefit from in vitro systems for the identification and the study of resistant variants. We report the use HCV subgenomic replicons to isolate and characterize mutants resistant to a protease inhibitor. Taking advantage of the replicons' ability to transduce resistance to neomycin, we selected replicons with decreased sensitivity to the inhibitor by culturing the host cells in the presence of the inhibitor and neomycin. The selected replicons replicated to the same extent as those in parental cells. Sequence analysis followed by transfection of replicons containing isolated mutations revealed that resistance was mediated by amino acid substitutions in the protease. These results were confirmed by in vitro experiments with mutant enzymes and by modeling the inhibitor in the three-dimensional structure of the protease.

scholarly journals Identification, Characterization, and Three-Dimensional Structure of the Novel Circular Bacteriocin, Enterocin NKR-5-3B, fromEnterococcus faecium

Biochemistry ◽  
2015 ◽  
Vol 54 (31) ◽  
pp. 4863-4876 ◽  
Author(s):  
Kohei Himeno ◽  
K. Johan Rosengren ◽  
Tomoko Inoue ◽  
Rodney H. Perez ◽  
Michelle L. Colgrave ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
The Novel ◽  
Three Dimensional Structure ◽  
Circular Bacteriocin

scholarly journals EXPRESSION OF THE MICROFOLD CELLS IN THREE-DIMENSIONAL COCULTURE SYSTEM FOR IN VITRO CULTIVATION OF HUMAN NOROVIRUS

2019 ◽  
pp. 71-74
Author(s):  
MIZANURFAKHRI GHAZALI ◽  
SHARANIZA AB-RAHIM ◽  
MUDIANA MUHAMAD
Keyword(s):  
Three Dimensional ◽  
In Vitro Cultivation ◽  
Optimum Number ◽  
M Cells ◽  
Apical Surface ◽  
Alginate Hydrogel ◽  
Human Norovirus ◽  
Protein Marker ◽  
Hydrogel Beads

Introduction: Human Norovirus (HuNoV), a food-borne virus is the leading cause for acute gastroenteritis. However, its inability to propagate in vitropersists as major challenge in understanding HuNoV biology.Objective: This study aims to determine an effective culture system for HuNoV.Methods: The Caco-2 cells were cocultured with Raji B cells on alginate hydrogel beads. Scanning electron microscopy (SEM) was performed to confirmthe three-dimensional (3D) cells morphology. Western blot (WB) analysis was performed to detect protein markers expressed by Microfold (M) cells.Results: Optimization of Caco-2 cells monoculture in the alginate hydrogel beads showed optimum number of cells of 1 × 106 cells/ml, indicatedby the intact structure of the beads. Result of SEM showed clear structure of monoculture in the alginate hydrogel beads indicated by the presenceof smooth and regular apical surface while the coculture showed reduced apical surface of M cells. The result of WB showed downregulation ofUlex europaeus antibody expression.Conclusion: It is evident that the expression of M cells grown in 3D alginate hydrogel beads was successful, indicated by the structural morphologyseen under SEM as well as expression of protein marker by M cells. This established in vitro system is highly potential for cultivation of HuNoV.

Rational humanization of the powerful antithrombotic anti-GPIbα antibody: 6B4

2006 ◽  
Vol 96 (11) ◽  
pp. 671-684 ◽  
Author(s):  
Alexandre Fontayne ◽  
Karen Vanhoorelbeke ◽  
Inge Pareyn ◽  
Isabel Van Rompaey ◽  
Muriel Meiring ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Three Dimensional ◽  
Vector System ◽  
Dimensional Structure ◽  
Fab Fragment ◽  
Variable Regions ◽  
Significant Prolongation ◽  
Von Willebrand ◽  
First Time

SummaryFab-fragments of the monoclonal antibody 6B4, raised against human glycoprotein Ibα (GPIbα), have a powerful antithrombotic effect in baboons by blocking the GPIbα binding site for von Willebrand factor (VWF), without significant prolongation of the skin bleeding time. In order to bring this antibody to the clinic,we here humanized for the first time an anti-human GPIbα by variable-domain resurfacing guided by computer modeling. First, the genes coding for the variable regions of the heavy and light chains of 6B4 were cloned and sequenced. Based on this,a three-dimensional structure of the Fv-fragment was constructed by using homology-based modeling, and with this and comparison with antibodies with known structure,”murine” putative immunogenic residues which are exposed, were changed for “human-like” residues. The humanized Fab-fragment, h6B4-Fab, was constructed in the pKaneo vector system, expressed and purified and showed in vitro an unaltered, even slightly higher binding affinity for its antigen than the murine form as determined by different ELISA set-ups and surface plasmon resonance. Finally, injection of doses of 0.1 to 1.5 mg/kg of h6B4-Fab in baboons showed that both pharmacokinetics and ex-vivo bio-activity of the molecule were to a large extent preserved.In conclusion, the method used here to humanize 6B4 by resurfacing resulted in a fully active derivative, which is now ready for further development.

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