scholarly journals The interleaved partial active shape model (IPASM) search algorithm – towards 3D ultrasound-based bone surface reconstruction

10.29007/rbgl ◽  
2019 ◽  
Author(s):  
Benjamin Hohlmann ◽  
Klaus Radermacher
Keyword(s):  
Search Algorithm ◽  
Three Dimensional ◽  
3D Ultrasound ◽  
Three Dimensional Model ◽  
In Vivo Experiments ◽  
Distal Surface ◽  
Cheap Alternative ◽  
Orthopedic Applications

Several orthopedic applications require a three-dimensional model of the bone. Ultrasound is a radiation-free and cheap alternative to the state-of-the-art imaging modalities if its limitations in terms of image quality and viewing range can be overcome. This work presents in-vitro as well as in-vivo experiments evaluating the IPASM search, a method for combined segmentation, registration as well as extrapolation. The algorithm is capable to reconstruct the distal surface of a phantom femur with an average surface distance error of roughly 1mm in case of in-vitro as well as below 2mm for in-vivo records, even if the shape varies strongly from the initial model.

scholarly journals The Challenging Melanoma Landscape: From Early Drug Discovery to Clinical Approval

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3088
Author(s):  
Mariana Matias ◽  
Jacinta O. Pinho ◽  
Maria João Penetra ◽  
Gonçalo Campos ◽  
Catarina Pinto Reis ◽  
...  
Keyword(s):  
Therapeutic Potential ◽  
Drug Evaluation ◽  
Three Dimensional ◽  
Experimental Models ◽  
In Vivo Studies ◽  
Murine Models ◽  
In Vivo Experiments ◽  
Novel Therapeutic Strategies

Melanoma is recognized as the most dangerous type of skin cancer, with high mortality and resistance to currently used treatments. To overcome the limitations of the available therapeutic options, the discovery and development of new, more effective, and safer therapies is required. In this review, the different research steps involved in the process of antimelanoma drug evaluation and selection are explored, including information regarding in silico, in vitro, and in vivo experiments, as well as clinical trial phases. Details are given about the most used cell lines and assays to perform both two- and three-dimensional in vitro screening of drug candidates towards melanoma. For in vivo studies, murine models are, undoubtedly, the most widely used for assessing the therapeutic potential of new compounds and to study the underlying mechanisms of action. Here, the main melanoma murine models are described as well as other animal species. A section is dedicated to ongoing clinical studies, demonstrating the wide interest and successful efforts devoted to melanoma therapy, in particular at advanced stages of the disease, and a final section includes some considerations regarding approval for marketing by regulatory agencies. Overall, considerable commitment is being directed to the continuous development of optimized experimental models, important for the understanding of melanoma biology and for the evaluation and validation of novel therapeutic strategies.

scholarly journals 3D Reconstruction of HvRNASET2 Molecule to Understand Its Antibacterial Role

2020 ◽  
Vol 21 (24) ◽  
pp. 9722
Author(s):  
Nicolò Baranzini ◽  
Laura Pulze ◽  
Marcella Reguzzoni ◽  
Rossella Roncoroni ◽  
Viviana Teresa Orlandi ◽  
...  
Keyword(s):  
Light Transmission ◽  
Three Dimensional ◽  
Lipoteichoic Acid ◽  
Type I ◽  
Phagocytic Cells ◽  
In Vivo Experiments ◽  
Macrophage Phagocytosis ◽  
Bacterial Aggregates

Recent studies performed on the invertebrate model Hirudo verbana (medicinal leech) suggest that the T2 ribonucleic enzyme HvRNASET2 modulates the leech’s innate immune response, promoting microbial agglutination and supporting phagocytic cells recruitment in challenged tissues. Indeed, following injection of both lipoteichoic acid (LTA) and Staphylococcus aureus in the leech body wall, HvRNASET2 is expressed by leech type I granulocytes and induces bacterial aggregation to aid macrophage phagocytosis. Here, we investigate the HvRNASET2 antimicrobial role, in particular assessing the effects on the Gram-negative bacteria Escherichia coli. For this purpose, starting from the three-dimensional molecule reconstruction and in silico analyses, the antibacterial activity was evaluated both in vitro and in vivo. The changes induced in treated bacteria, such as agglutination and alteration in wall integrity, were observed by means of light, transmission and scanning electron microscopy. Moreover, immunogold, AMPs (antimicrobial peptides) and lipopolysaccharide (LPS) binding assays were carried out to evaluate HvRNASET2 interaction with the microbial envelopes and the ensuing ability to affect microbial viability. Finally, in vivo experiments confirmed that HvRNASET2 promotes a more rapid phagocytosis of bacterial aggregates by macrophages, representing a novel molecule for counteracting pathogen infections and developing alternative solutions to improve human health.

scholarly journals Identification of Novel Recognition Motifs and Regulatory Targets for the Yeast Actin-regulating Kinase Prk1p

2003 ◽  
Vol 14 (12) ◽  
pp. 4871-4884 ◽  
Author(s):  
Bo Huang ◽  
Guisheng Zeng ◽  
Alvin Y.J. Ng ◽  
Mingjie Cai
Keyword(s):  
Actin Cytoskeleton ◽  
Phosphorylation Site ◽  
Three Dimensional ◽  
Kinase Domain ◽  
Yeast Genome ◽  
Three Dimensional Model ◽  
Recognition Sequence ◽  
Yeast Saccharomyces Cerevisiae

Prk1p is a serine/threonine kinase involved in the regulation of the actin cytoskeleton organization in the yeast Saccharomyces cerevisiae. Previously, we have identified LxxQxTG as the phosphorylation site of Prk1p. In this report, the recognition sequence for Prk1p is investigated more thoroughly. It is found that the presence of a hydrophobic residue at the position of P-5 is necessary for Prk1p phosphorylation and L, I, V, and M are all able to confer the phosphorylation at various efficiencies. The residue flexibility at P-2 has also been identified to include Q, N, T, and S. A homology-based three-dimensional model of the kinase domain of Prk1p provided some structural interpretations for these substrate specificities. The characterization of the [L/I/V/M]xx[Q/N/T/S]xTG motif led to the identification of a spectrum of potential targets for Prk1p from yeast genome. One of them, Scd5p, which contains three LxxTxTG motifs and is previously known to be important for endocytosis and actin organization, has been chosen to demonstrate its relationship with Prk1p. Phosphorylation of Scd5p by Prk1p at the three LxxTxTG motifs could be detected in vitro and in vivo, and deletion of PRK1 suppressed the defects in actin cytoskeleton and endocytosis in one of the scd5 mutants. These results allowed us to conclude that Scd5p is likely another regulatory target of Prk1p.

scholarly journals Mutagenesis and Molecular Modeling Reveal Three Key Extracellular Loops of the Membrane Receptor HasR That Are Involved in Hemophore HasA Binding

2007 ◽  
Vol 189 (14) ◽  
pp. 5379-5382 ◽  
Author(s):  
Clément Barjon ◽  
Karine Wecker ◽  
Nadia Izadi-Pruneyre ◽  
Philippe Delepelaire
Keyword(s):  
Molecular Modeling ◽  
Outer Membrane ◽  
Three Dimensional ◽  
Membrane Receptor ◽  
Dimensional Model ◽  
Outer Membrane Receptor ◽  
Three Dimensional Model ◽  
Extracellular Loops

ABSTRACT On the basis of the three-dimensional model of the heme/hemophore TonB-dependent outer membrane receptor HasR, mutants with six-residue deletions in the 11 putative extracellular loops were generated. Although all mutants continued to be active TonB-dependent heme transporters, mutations in three loops abolished hemophore HasA binding both in vivo and in vitro.

scholarly journals Recent Advances in Three-Dimensional Multicellular Spheroid Culture and Future Development

Micromachines ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 96
Author(s):  
Honglin Shen ◽  
Shuxiang Cai ◽  
Chuanxiang Wu ◽  
Wenguang Yang ◽  
Haibo Yu ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Multicellular Spheroids ◽  
Three Dimensional Model ◽  
Advantages And Disadvantages ◽  
High Throughput Drug Screening ◽  
Tumor Research ◽  
Basic Biology ◽  
And Function

Three-dimensional multicellular spheroids (MCSs) have received extensive attention in the field of biomedicine due to their ability to simulate the structure and function of tissues in vivo more accurately than traditional in vitro two-dimensional models and to simulate cell–cell and cell extracellular matrix (ECM) interactions. It has become an important in vitro three-dimensional model for tumor research, high-throughput drug screening, tissue engineering, and basic biology research. In the review, we first summarize methods for MCSs generation and their respective advantages and disadvantages and highlight the advances of hydrogel and microfluidic systems in the generation of spheroids. Then, we look at the application of MCSs in cancer research and other aspects. Finally, we discuss the development direction and prospects of MCSs

scholarly journals Experimental study of tissue-engineered urethra with collagen / chitosan composite as scaffolds

2020 ◽  
Author(s):  
Zhai Hongfeng ◽  
Qiu Changhong ◽  
Jin Jun ◽  
Shao Xin
Keyword(s):  
New Zealand ◽  
Epithelial Cells ◽  
Cell Activity ◽  
Three Dimensional ◽  
Volume Ratio ◽  
In Vivo Experiments ◽  
High Area ◽  
Chitosan Composite

AbstractIn this article we investigated the preparation of tissue-engineered urethra by using the urethral epithelial subculture cells of male New Zealand young rabbits. We inoculated the epithelial cells of urinary mucosa of male New Zealand young rabbits on collagen, chitosan and collagen chitosan composite as scaffolds to prepare tissue-engineered urethra. The results of inverted phase contrast microscope, HE staining and scanning electron microscope of three kinds of tissue-engineered urethra were compared. What’s more, we reported a new method for quantitative and rapid detection of epithelial cell activity of urinary mucosa in situ by Interactive Laser Cytometer. The collagen chitosan composite was more similar to the extracellular matrix of mammalian. Its three-dimensional porous structure had a high area volume ratio, which was conducive to cell adhesion, growth and metabolism. In vitro, the urethral epithelial cells had been cultured on collagen chitosan composite, and the tissue-engineered urethra was successfully prepared, which laid a solid foundation for further in vivo experiments.

Vibration-Assisted Insertion of Flexible Neural Microelectrodes With Bio-Dissolvable Guides for Medical Implantation

2021 ◽  
Author(s):  
Yi Wang ◽  
Yen Yu Ian Shih ◽  
Yuan-shin Lee
Keyword(s):  
Tissue Damage ◽  
Three Dimensional ◽  
Insertion Technique ◽  
Neural Electrode ◽  
In Vivo Experiments ◽  
Neural Probe ◽  
Electrode Insertion ◽  
Neural Microelectrodes

Abstract This paper presents vibration-assisted insertion of flexible neural electrodes with bio-dissolvable guides to deliver accurate microprobe insertion with minimized tissue damage. Invasive flexible neural microprobe is an important new tool for neuromodulation and recording research for medical neurology treatment applications. Flexible neural electrode probes are susceptible to bending and buckling during surgical implantation due to the thin and flexible soft substrates. Inspired by insects in nature, a vibration-assisted insertion technique is developed for flexible neural electrode insertion to deliver accurate microprobe insertion with minimized tissue damage. A three-dimensional combined longitudinal-twisting (L&T) vibration is used to reduce the insertion friction force, and thus reducing soft tissue damage. To reduce the flexible microelectrode buckling during surgical insertion, a bio-dissolvable Polyethylene glycol (PEG) guide is developed for the enhancement of flexible neural probe stiffness. Combining these two methods, the insertion performance of the flexible neural probe is significantly improved. Both the in vitro and the in vivo experiments were conducted to validate the proposed techniques.

Emerging Vascular Applications of Magnetic Resonance Imaging: A Picture is Worth More than a Thousand Words

Vascular ◽  
2006 ◽  
Vol 14 (6) ◽  
pp. 366-371 ◽  
Author(s):  
Tamara N. Fitzgerald ◽  
Akihito Muto ◽  
Fabio Akimaro Kudo ◽  
Jose Mario Pimiento ◽  
Robert Todd Constable ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Three Dimensional ◽  
Quantitative Information ◽  
Data Set ◽  
Vascular Intervention ◽  
In Vivo Experiments ◽  
Blood Flow Dynamics

Vascular applications of magnetic resonance (MR) imaging are reviewed, with emphasis on algorithms that use nonpictorial information contained in the MR data set. Current clinical vascular practice generally limits use of MR angiography and three-dimensional vessel images to qualitative pictorial rendering without routinely using the available quantitative information contained within the MR data. This review is dedicated to recent advances that include characterization of vessel histology, assessment of carotid plaque vulnerability, characterization of blood flow dynamics, quantitative analysis of disease severity, and prediction of vascular intervention outcome. Examples from histologic preparation, in vitro and in vivo experiments, are discussed, with an emphasis on potential clinical applications and advances in acquisition technology.

scholarly journals The combination of multi-functional ingredients-loaded hydrogels and three-dimensional printed porous titanium alloys for infective bone defect treatment

2020 ◽  
Vol 11 ◽  
pp. 204173142096579
Author(s):  
Shichong Qiao ◽  
Dongle Wu ◽  
Zuhao Li ◽  
Yu Zhu ◽  
Fei Zhan ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Bone Ingrowth ◽  
Three Dimensional ◽  
Supramolecular Assembly ◽  
Porous Titanium ◽  
Novel Therapy ◽  
In Vivo Experiments ◽  
Marrow Mesenchymal Stem Cells

Biomaterial with the dual-functions of bone regeneration and antibacterial is a novel therapy for infective bone defects. Three-dimensional (3D)-printed porous titanium (pTi) benefits bone ingrowth, but its microporous structure conducive to bacteria reproduction. Herein, a multifunctional hydrogel was prepared from dynamic supramolecular assembly of sodium tetraborate (Na2B4O7), polyvinyl alcohol (PVA), silver nanoparticles (AgNPs) and tetraethyl orthosilicate (TEOS), and composited with pTi as an implant system. The pTi scaffolds have ideal pore size and porosity matching with bone, while the supramolecular hydrogel endows pTi scaffolds with antibacterial and biological activity. In vitro assessments indicated the 3D composite implant was biocompatible, promoted bone marrow mesenchymal stem cells (BMSCs) proliferation and osteogenic differentiation, and inhibited bacteria, simultaneously. In vivo experiments further demonstrated that the implant showed effective antibacterial ability while promoting bone regeneration. Besides distal femur defect, the innovative scaffolds may also serve as an ideal biomaterial (e.g. dental implants) for other contaminated defects.

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