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1.
Adv Healthc Mater ; : e2400077, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38599586

RESUMO

Following biomaterial implantation, a failure to resolve inflammation during the formation of a fracture hematoma can significantly limit the biomaterial's ability to facilitate bone regeneration. This study aims to combine the immunomodulatory and osteogenic effects of BMP-7 and IL-10 with the regenerative capacity of collagen-hydroxyapatite (CHA) scaffolds to enhance in vitro mineralization in a hematoma-like environment. Incubation of CHA scaffolds with human whole blood leads to rapid adsorption of fibrinogen, significant stiffening of the scaffold, and the formation of a hematoma-like environment characterized by a limited capacity to support the infiltration of human bone progenitor cells, a significant upregulation of inflammatory cytokines and acute phase proteins, and significantly reduced osteoconductivity. CHA scaffolds functionalized with BMP-7 and IL-10 significantly downregulate the production of key inflammatory cytokines, including IL-6, IL-8, and leptin, creating a more permissive environment for mineralization, ultimately enhancing the biomaterial's osteoconductivity. In conclusion, targeting the onset of inflammation in the early phase of bone healing using BMP-7 and IL-10 functionalized CHA scaffolds is a promising approach to effectively downregulate inflammatory processes, while fostering a more permissive environment for bone regeneration.

2.
Chem Commun (Camb) ; 60(38): 5090-5091, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38683137

RESUMO

Correction for 'Influence of a neighbouring Cu centre on electro- and photocatalytic CO2 reduction by Fe-Mabiq' by Kerstin Rickmeyer et al., Chem. Commun., 2024, 60, 819-822, https://doi.org/10.1039/D3CC04777F.

3.
Surg Endosc ; 38(5): 2483-2496, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38456945

RESUMO

OBJECTIVE: Evaluation of the benefits of a virtual reality (VR) environment with a head-mounted display (HMD) for decision-making in liver surgery. BACKGROUND: Training in liver surgery involves appraising radiologic images and considering the patient's clinical information. Accurate assessment of 2D-tomography images is complex and requires considerable experience, and often the images are divorced from the clinical information. We present a comprehensive and interactive tool for visualizing operation planning data in a VR environment using a head-mounted-display and compare it to 3D visualization and 2D-tomography. METHODS: Ninety medical students were randomized into three groups (1:1:1 ratio). All participants analyzed three liver surgery patient cases with increasing difficulty. The cases were analyzed using 2D-tomography data (group "2D"), a 3D visualization on a 2D display (group "3D") or within a VR environment (group "VR"). The VR environment was displayed using the "Oculus Rift ™" HMD technology. Participants answered 11 questions on anatomy, tumor involvement and surgical decision-making and 18 evaluative questions (Likert scale). RESULTS: Sum of correct answers were significantly higher in the 3D (7.1 ± 1.4, p < 0.001) and VR (7.1 ± 1.4, p < 0.001) groups than the 2D group (5.4 ± 1.4) while there was no difference between 3D and VR (p = 0.987). Times to answer in the 3D (6:44 ± 02:22 min, p < 0.001) and VR (6:24 ± 02:43 min, p < 0.001) groups were significantly faster than the 2D group (09:13 ± 03:10 min) while there was no difference between 3D and VR (p = 0.419). The VR environment was evaluated as most useful for identification of anatomic anomalies, risk and target structures and for the transfer of anatomical and pathological information to the intraoperative situation in the questionnaire. CONCLUSIONS: A VR environment with 3D visualization using a HMD is useful as a surgical training tool to accurately and quickly determine liver anatomy and tumor involvement in surgery.


Assuntos
Imageamento Tridimensional , Tomografia Computadorizada por Raios X , Realidade Virtual , Humanos , Tomografia Computadorizada por Raios X/métodos , Feminino , Masculino , Hepatectomia/métodos , Hepatectomia/educação , Adulto , Adulto Jovem , Tomada de Decisão Clínica , Interface Usuário-Computador , Neoplasias Hepáticas/cirurgia , Neoplasias Hepáticas/diagnóstico por imagem
4.
Chem Commun (Camb) ; 60(7): 819-822, 2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38113085

RESUMO

Electrocatalytic and photocatalytic CO2 reduction by a heterobimetallic Cu/Fe-Mabiq complex were examined and compared to the monometallic [Fe(Mabiq)]+. The neighbouring Cu-Xantphos unit leads to marked changes in the electrocatalytic mechanism and enhanced photocatalytic performance.

5.
Biomaterials ; 299: 122165, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37290157

RESUMO

The control of supramolecular complexes in living systems at the molecular level is an important goal in life-sciences. Spatiotemporal organization of molecular distribution & flow of such complexes are essential physicochemical processes in living cells and important for pharmaceutical processes. Membraneless organelles (MO) found in eukaryotic cells, formed by liquid-liquid phase-separation (LLPS) of intrinsically disordered proteins (IDPs) control and adjust intracellular organization. Artificially designed compartments based on LLPS open up a novel pathway to control chemical flux and partition in vitro and in vivo. We designed a library of chemically precisely defined block copolymer-like proteins based on elastin-like proteins (ELPs) with defined charge distribution and type, as well as polar and hydrophobic block domains. This enables the programmability of physicochemical properties and to control adjustable LLPS in vivo attaining control over intracellular partitioning and flux as role model for in vitro and in vivo applications. Tailor-made ELP-like block copolymer proteins exhibiting IDP-behavior enable LLPS formation in vitro and in vivo allowing the assembly of membrane-based and membraneless superstructures via protein phase-separation in E. coli. Subsequently, we demonstrate the responsiveness of protein phase-separated spaces (PPSSs) to environmental physicochemical triggers and their selective, charge-dependent and switchable interaction with DNA or extrinsic and intrinsic molecules enabling their selective shuttling across semipermeable phase boundaries including (cell)membranes. This paves the road for adjustable artificial PPSS-based storage and reaction spaces and the specific transport across phase boundaries for applications in pharmacy and synthetic biology.


Assuntos
Escherichia coli , Proteínas Intrinsicamente Desordenadas , Escherichia coli/metabolismo , Proteínas Intrinsicamente Desordenadas/química , Citoplasma/metabolismo , Organelas/metabolismo , Membrana Celular/metabolismo
6.
Biotechnol Bioeng ; 119(12): 3584-3595, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36109834

RESUMO

Modern biotechnological laboratories are equipped with advanced parallel mini-bioreactor facilities that can perform sophisticated cultivation strategies (e.g., fed-batch or continuous) and generate significant amounts of measurement data. These systems require not only optimal experimental designs that find the best conditions in very large design spaces, but also algorithms that manage to operate a large number of different cultivations in parallel within a well-defined and tightly constrained operating regime. Existing advanced process control algorithms have to be tailored to tackle the specific issues of such facilities such as: a very complex biological system, constant changes in the metabolic activity and phenotypes, shifts of pH and/or temperature, and metabolic switches, to name a few. In this study we implement a model predictive control (MPC) framework to demonstrate: (1) the challenges in terms of mathematical model structure, state, and parameter estimation, and optimization under highly nonlinear and stiff dynamics in biological systems, (2) the adaptations required to enable the application of MPC in high throughput bioprocess development, and (3) the added value of MPC implementations when operating parallel mini-bioreactors aiming to maximize the biomass concentration while coping with hard constrains on the dissolved oxygen tension profile.


Assuntos
Escherichia coli , Ensaios de Triagem em Larga Escala , Escherichia coli/genética , Reatores Biológicos , Biotecnologia , Biomassa
7.
Front Bioeng Biotechnol ; 10: 878838, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35814018

RESUMO

Elastin-like proteins (ELPs) are polypeptides with potential applications as renewable bio-based high-performance polymers, which undergo a stimulus-responsive reversible phase transition. The ELP investigated in this manuscript-ELP[V2Y-45]-promises fascinating mechanical properties in biomaterial applications. Purification process scalability and purification performance are important factors for the evaluation of potential industrial-scale production of ELPs. Salt-induced precipitation, inverse transition cycling (ITC), and immobilized metal ion affinity chromatography (IMAC) were assessed as purification protocols for a polyhistidine-tagged hydrophobic ELP showing low-temperature transition behavior. IMAC achieved a purity of 86% and the lowest nucleic acid contamination of all processes. Metal ion leakage did not propagate chemical modifications and could be successfully removed through size-exclusion chromatography. The simplest approach using a high-salt precipitation resulted in a 60% higher target molecule yield compared to both other approaches, with the drawback of a lower purity of 60% and higher nucleic acid contamination. An additional ITC purification led to the highest purity of 88% and high nucleic acid removal. However, expensive temperature-dependent centrifugation steps are required and aggregation effects even at low temperatures have to be considered for the investigated ELP. Therefore, ITC and IMAC are promising downstream processes for biomedical applications with scale-dependent economical costs to be considered, while salt-induced precipitation may be a fast and simple alternative for large-scale bio-based polymer production.

8.
Surg Endosc ; 36(1): 126-134, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-33475848

RESUMO

BACKGROUND: Virtual reality (VR) with head-mounted displays (HMD) may improve medical training and patient care by improving display and integration of different types of information. The aim of this study was to evaluate among different healthcare professions the potential of an interactive and immersive VR environment for liver surgery that integrates all relevant patient data from different sources needed for planning and training of procedures. METHODS: 3D-models of the liver, other abdominal organs, vessels, and tumors of a sample patient with multiple hepatic masses were created. 3D-models, clinical patient data, and other imaging data were visualized in a dedicated VR environment with an HMD (IMHOTEP). Users could interact with the data using head movements and a computer mouse. Structures of interest could be selected and viewed individually or grouped. IMHOTEP was evaluated in the context of preoperative planning and training of liver surgery and for the potential of broader surgical application. A standardized questionnaire was voluntarily answered by four groups (students, nurses, resident and attending surgeons). RESULTS: In the evaluation by 158 participants (57 medical students, 35 resident surgeons, 13 attending surgeons and 53 nurses), 89.9% found the VR system agreeable to work with. Participants generally agreed that complex cases in particular could be assessed better (94.3%) and faster (84.8%) with VR than with traditional 2D display methods. The highest potential was seen in student training (87.3%), resident training (84.6%), and clinical routine use (80.3%). Least potential was seen in nursing training (54.8%). CONCLUSIONS: The present study demonstrates that using VR with HMD to integrate all available patient data for the preoperative planning of hepatic resections is a viable concept. VR with HMD promises great potential to improve medical training and operation planning and thereby to achieve improvement in patient care.


Assuntos
Cirurgiões , Realidade Virtual , Humanos , Fígado , Interface Usuário-Computador
9.
Angew Chem Int Ed Engl ; 61(3): e202112738, 2022 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-34806270

RESUMO

Elastin-like proteins (ELPs) are biologically important proteins and models for intrinsically disordered proteins (IDPs) and dynamic structural transitions associated with coacervates and liquid-liquid phase transitions. However, the conformational status below and above coacervation temperature and its role in the phase separation process is still elusive. Employing matrix least-squares global Boltzmann fitting of the circular dichroism spectra of the ELPs (VPGVG)20 , (VPGVG)40 , and (VPGVG)60 , we found that coacervation occurs sharply when a certain number of repeat units has acquired ß-turn conformation (in our sequence setting a threshold of approx. 20 repeat units). The character of the differential scattering of the coacervate suspensions indicated that this fraction of ß-turn structure is still retained after polypeptide assembly. Such conformational thresholds may also have a role in other protein assembly processes with implications for the design of protein-based smart materials.


Assuntos
Proteínas Intrinsicamente Desordenadas/química , Peptídeos/química , Termodinâmica , Dicroísmo Circular , Humanos , Proteínas Intrinsicamente Desordenadas/metabolismo , Modelos Moleculares , Peptídeos/metabolismo , Conformação Proteica
10.
J Vis Exp ; (158)2020 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-32338656

RESUMO

Tailored proteinaceous building blocks are versatile candidates for the assembly of supramolecular structures such as minimal cells, drug delivery vehicles and enzyme scaffolds. Due to their biocompatibility and tunability on the genetic level, Elastin-like proteins (ELP) are ideal building blocks for biotechnological and biomedical applications. Nevertheless, the assembly of protein based supramolecular structures with distinct physiochemical properties and good encapsulation potential remains challenging. Here we provide two efficient protocols for guided self-assembly of amphiphilic ELPs into supramolecular protein architectures such as spherical coacervates, fibers and stable vesicles. The presented assembly protocols generate Protein Membrane-Based Compartments (PMBCs) based on ELPs with adaptable physicochemical properties. PMBCs demonstrate phase separation behavior and reveal method dependent membrane fusion and are able to encapsulate chemically diverse fluorescent cargo molecules. The resulting PMBCs have a high application potential as a drug formulation and delivery platform, artificial cell, and compartmentalized reaction space.


Assuntos
Portadores de Fármacos/síntese química , Sistemas de Liberação de Medicamentos/métodos , Elastina/química , Materiais Biocompatíveis , Portadores de Fármacos/química , Membranas Artificiais , Polimerização
11.
ACS Synth Biol ; 9(4): 827-842, 2020 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-32130855

RESUMO

The investigation of complex biological processes in vivo often requires defined multiple bioconjugation and positioning of functional entities on 3D structures. Prominent examples include spatially defined protein complexes in nature, facilitating efficient biocatalysis of multistep reactions. Mimicking natural strategies, synthetic scaffolds should comprise bioorthogonal conjugation reactions and allow for absolute stoichiometric quantification as well as facile scalability through scaffold reproduction. Existing in vivo scaffolding strategies often lack covalent conjugations on geometrically confined scaffolds or precise quantitative characterization. Addressing these shortcomings, we present a bioorthogonal dual conjugation platform based on genetically encoded artificial compartments in vivo, comprising two distinct genetically encoded covalent conjugation reactions and their precise stoichiometric quantification. The SpyTag/SpyCatcher (ST/SC) bioconjugation and the controllable strain-promoted azide-alkyne cycloaddition (SPAAC) were implemented on self-assembled protein membrane-based compartments (PMBCs). The SPAAC reaction yield was quantified to be 23% ± 3% and a ST/SC surface conjugation yield of 82% ± 9% was observed, while verifying the compatibility of both chemical reactions as well as enhanced proteolytic stability. Using tandem mass spectrometry, absolute concentrations of the proteinaceous reactants were calculated to be 0.11 ± 0.05 attomol/cell for PMBC surface-tethered mCherry-ST-His and 0.22 ± 0.09 attomol/cell for PMBC-constituting pAzF-SC-E20F20-His. The established in vivo conjugation platform enables quantifiable protein-protein interaction studies on geometrically defined scaffolds and paves the road to investigate effects of scaffold-tethering on enzyme activity.


Assuntos
Conjugação Genética/fisiologia , Espaço Intracelular/metabolismo , Engenharia Metabólica/métodos , Biologia Sintética/métodos , Conjugação Genética/genética , Escherichia coli/citologia , Escherichia coli/genética , Escherichia coli/metabolismo , Espaço Intracelular/fisiologia , Modelos Biológicos , Proteínas/genética , Proteínas/metabolismo
12.
Harmful Algae ; 92: 101744, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32113611

RESUMO

The dinoflagellate genus Alexandrium comprises species that produce highly potent neurotoxins known as paralytic shellfish toxins (PST), and bioactive extracellular compounds (BEC) of unknown structure and ecological significance. The toxic bloom-forming species, Alexandrium minutum, is distributed worldwide and adversely affects many bivalves including the commercially and ecologically important Pacific oyster, Crassostrea gigas. In France, recurrent A. minutum blooms can co-occur with C. gigas spawning and larval development, and may endanger recruitment and population renewal. The present study explores how A. minutum affects oyster early development by exposing embryos and larvae, under controlled laboratory conditions, to two strains of A. minutum, producing only BEC or both PST and BEC. Results highlight the major role of BEC in A. minutum toxicity upon oyster development. The BEC strain caused lysis of embryos, the most sensitive stage to A. minutum toxicity among planktonic life stages. In addition, the non-PST-producing A. minutum strain inhibited hatching, disrupted larval swimming behavior, feeding, growth, and induced drastic decreases in survival and settlement of umbonate and eyed larvae (9 and 68 %, respectively). The findings indicated PST accumulation in oyster larvae (e.g. umbonate stages), possibly impairing development and settlement of larvae in response to the PST-producing strain. This work provides evidences that A. minutum blooms could hamper settlement of shellfish.


Assuntos
Crassostrea , Dinoflagellida , Toxinas Marinhas , Animais , França , Larva , Toxinas Marinhas/toxicidade
13.
Langmuir ; 35(29): 9593-9610, 2019 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-31287709

RESUMO

The nature of the first prebiotic compartments and their possible minimal molecular composition is of great importance in the origin of life scenarios. Current protocell model membranes are proposed to be lipid-based. This paradigm has several shortcomings such as limited membrane stability of monoacyl lipid-based membranes (e.g., fatty acids), missing pathways to synthesize protocell membrane components (e.g., phospholipids) under early earth conditions, and the requirement for different classes of molecules for the formation of compartments and the catalysis of reactions. Amino acids on the other hand are known to arise and persist with remarkable abundance under early earth conditions since the fundamental Miller-Urey experiments. They were also postulated early to form protocellular structures, for example, proteinoid capsules. Here, we present a protocell model constituted by membranes assembled from amphiphilic proteins based on prebiotic amino acids. Self-assembled dynamic protein membrane-based compartments (PMBCs) are impressively stable and compatible with prevalent cellular membrane constituents forming protein-only or protein-lipid hybrid membranes. They can embed processes essential for extant living cells, such as enclosure of molecules, membrane fusion, phase separation, and complex biosynthetic elements from modern cells demonstrating "upward" compatibility. Our findings suggest that prebiotic PMBCs represent a new type of protocell as a possible ancestor of current lipid-based cells. The presented prebiotic PMBC model can be used to design artificial cells, important for the study of structural, catalytic, and evolutionary pathways related to the emergence of life.


Assuntos
Ácidos Graxos/química , Bicamadas Lipídicas/química , Simulação de Dinâmica Molecular , Origem da Vida , Proteínas/química , Tamanho da Partícula , Propriedades de Superfície
14.
Chembiochem ; 20(20): 2618-2632, 2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31183952

RESUMO

Life in its molecular context is characterized by the challenge of orchestrating structure, energy and information processes through compartmentalization and chemical transformations amenable to mimicry of protocell models. Here we present an alternative protocell model incorporating dynamic membranes based on amphiphilic elastin-like proteins (ELPs) rather than phospholipids. For the first time we demonstrate the feasibility of combining vesicular membrane formation and biocatalytic activity with molecular entities of a single class: proteins. The presented self-assembled protein-membrane-based compartments (PMBCs) accommodate either an anabolic reaction, based on free DNA ligase as an example of information transformation processes, or a catabolic process. We present a catabolic process based on a single molecular entity combining an amphiphilic protein with tobacco etch virus (TEV) protease as part of the enclosure of a reaction space and facilitating selective catalytic transformations. Combining compartmentalization and biocatalytic activity by utilizing an amphiphilic molecular building block with and without enzyme functionalization enables new strategies in bottom-up synthetic biology, regenerative medicine, pharmaceutical science and biotechnology.


Assuntos
Células Artificiais/química , Elastina/química , Endopeptidases/química , Células Artificiais/citologia , Biocatálise , Biologia Sintética
15.
Small ; 15(30): e1900163, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31173449

RESUMO

The molecular structuring of complex architectures and the enclosure of space are essential requirements for technical and living systems. Self-assembly of supramolecular structures with desired shape, size, and stability remains challenging since it requires precise regulation of physicochemical and conformational properties of the components. Here a general platform for controlled self-assembly of tailored amphiphilic elastin-like proteins into desired supramolecular protein assemblies ranging from spherical coacervates over molecularly defined twisted fibers to stable unilamellar vesicles is introduced. The described assembly protocols efficiently yield protein membrane-based compartments (PMBC) with adjustable size, stability, and net surface charge. PMBCs demonstrate membrane fusion and phase separation behavior and are able to encapsulate structurally and chemically diverse cargo molecules ranging from small molecules to naturally folded proteins. The ability to engineer tailored supramolecular architectures with defined fusion behavior, tunable properties, and encapsulated cargo paves the road for novel drug delivery systems, the design of artificial cells, and confined catalytic nanofactories.


Assuntos
Elastina/química , Tensoativos/química , Dicroísmo Circular , Elastina/ultraestrutura , Fluorescência , Membranas Artificiais , Nanofibras/química , Nanofibras/ultraestrutura , Tamanho da Partícula , Conformação Proteica , Temperatura
16.
J Mol Med (Berl) ; 96(8): 765-775, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29934777

RESUMO

Immune-mediated heparin-induced thrombocytopenia (HIT) is the clinically most important adverse drug reaction (ADR) in response to heparin therapy characterized by a prothrombotic state despite a decrease in platelet count. We conducted a genome-wide association study in 96 suspected HIT cases and 96 controls to explore the genetic predisposition for HIT within a case-control pharmacovigilance study followed by replication in additional 86 cases and 86 controls from the same study. One single nucleotide polymorphism (SNP, rs1433265, P = 6.5 × 10-5, odds ratio (OR) 2.79) from 16 identified SNPs was successfully replicated (P = 1.5 × 10-4, OR 2.77; combined data set P = 2.7 × 10-8, OR 2.77) and remained the most strongly associated SNP after imputing locus genotypes. Fine mapping revealed a significantly associated risk-conferring haplotype (P = 4.9 × 10-6, OR 2.41). In order to find rare variants contributing to the association signals, we applied a targeted resequencing approach in a subgroup of 73 HIT patients and 23 controls for the regions with the 16 most strongly HIT-associated SNPs. C-alpha testing was applied to test for the impact of rare variants and we detected two candidate genes, the discoidin domain receptor tyrosine kinase 1 (DDR1, P = 3.6 × 10-2) and the multiple C2 and transmembrane domain containing 2 (MCTP2, P = 4.5 × 10-2). For the genes interactor of little elongation complex ELL subunit 1 (ICE1) and a disintegrin-like and metalloproteinase with thrombospondin type 1 motif, 16 (ADAMTS16) nearby rs1433265, we identified several missense variants. Although replication in an independent population is warranted, these findings provide a basis for future studies aiming to identify and characterize genetic susceptibility factors for HIT. KEY MESSAGES: We identified and validated a HIT-associated locus on chromosome 5. Targeted NGS analysis for rare variants identifies DDR1 and MCTP2 as novel candidates. In addition, missense variants for ADAMTS16 and ICE1 were identified in the locus.


Assuntos
Anticoagulantes/efeitos adversos , Cromossomos Humanos Par 5 , Predisposição Genética para Doença , Heparina/efeitos adversos , Locos de Características Quantitativas , Trombocitopenia/etiologia , Idoso , Alelos , Biomarcadores , Estudos de Casos e Controles , Feminino , Estudo de Associação Genômica Ampla , Genótipo , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Testes Farmacogenômicos , Polimorfismo de Nucleotídeo Único , Trombocitopenia/sangue , Trombocitopenia/diagnóstico
17.
Int J Comput Assist Radiol Surg ; 13(5): 741-748, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29551011

RESUMO

PURPOSE: The data which is available to surgeons before, during and after surgery is steadily increasing in quantity as well as diversity. When planning a patient's treatment, this large amount of information can be difficult to interpret. To aid in processing the information, new methods need to be found to present multimodal patient data, ideally combining textual, imagery, temporal and 3D data in a holistic and context-aware system. METHODS: We present an open-source framework which allows handling of patient data in a virtual reality (VR) environment. By using VR technology, the workspace available to the surgeon is maximized and 3D patient data is rendered in stereo, which increases depth perception. The framework organizes the data into workspaces and contains tools which allow users to control, manipulate and enhance the data. Due to the framework's modular design, it can easily be adapted and extended for various clinical applications. RESULTS: The framework was evaluated by clinical personnel (77 participants). The majority of the group stated that a complex surgical situation is easier to comprehend by using the framework, and that it is very well suited for education. Furthermore, the application to various clinical scenarios-including the simulation of excitation propagation in the human atrium-demonstrated the framework's adaptability. As a feasibility study, the framework was used during the planning phase of the surgical removal of a large central carcinoma from a patient's liver. CONCLUSION: The clinical evaluation showed a large potential and high acceptance for the VR environment in a medical context. The various applications confirmed that the framework is easily extended and can be used in real-time simulation as well as for the manipulation of complex anatomical structures.


Assuntos
Carcinoma Hepatocelular/cirurgia , Hepatectomia/educação , Neoplasias Hepáticas/cirurgia , Realidade Virtual , Idoso , Simulação por Computador , Estudos de Viabilidade , Feminino , Cirurgia Geral/educação , Humanos , Imageamento Tridimensional , Internato e Residência , Projetos Piloto , Treinamento por Simulação/métodos , Estudantes de Medicina , Procedimentos Cirúrgicos Operatórios/educação , Interface Usuário-Computador
18.
Biol Open ; 7(3)2018 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-29483075

RESUMO

Investigating the roles of chemical factors stimulating and inhibiting sperm motility is required to understand the mechanisms of spermatozoa movement. In this study, we described the composition of the seminal fluid (osmotic pressure, pH, and ions) and investigated the roles of these factors and salinity in initiating spermatozoa movement in the Pacific oyster, Crassostrea gigas The acidic pH of the gonad (5.82±0.22) maintained sperm in the quiescent stage and initiation of flagellar movement was triggered by a sudden increase of spermatozoa external pH (pHe) when released in seawater (SW). At pH 6.4, percentage of motile spermatozoa was three times higher when they were activated in SW containing 30 mM NH4Cl, which alkalinizes internal pH (pHi) of spermatozoa, compared to NH4Cl-free SW, revealing the role of pHi in triggering sperm movement. Percentage of motile spermatozoa activated in Na+-free artificial seawater (ASW) was highly reduced compared to ASW, suggesting that change of pHi triggering sperm motility was mediated by a Na+/H+ exchanger. Motility and swimming speed were highest in salinities between 33.8 and 42.7‰ (within a range of 0 to 50 ‰), and pH values above 7.5 (within a range of 4.5 to 9.5).

19.
Pharmacoepidemiol Drug Saf ; 26(10): 1149-1155, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28544026

RESUMO

PURPOSE: Immune-mediated heparin-induced thrombocytopenia (HIT type II, HIT) is a potentially serious adverse drug reaction characterized by an increased risk of venous and arterial thrombosis. This study aimed to identify risk factors associated with the development of these complications. METHODS: Our study cohort included patients with HIT assembled in our pharmacovigilance center by reports from 51 collaborating hospitals in Berlin, Germany. To identify risk factors for thromboembolic complications, patients with thromboembolic events (cases) were compared to those without thromboembolic events (controls) in a case-control design. We applied univariable and multivariable logistic regression analysis to estimate odds ratios (OR) and corresponding 95% confidence intervals (CI) for potential risk factors of thromboembolic complications. RESULTS: Our cohort comprised 209 HIT patients. Of those, 53 developed thromboembolic complications. Most HIT patients received heparin for medical indications (42.1%) or in the context of cardiovascular surgery (40.2%). Of the 78 thromboembolic complications, 49 (63%) and 29 (37%) were observed in the venous and arterial vascular bed, respectively. The main locations were deep vein thrombosis (39.7%), pulmonary embolism (16.7%), and limb artery thrombosis (16.7%). In multivariable analysis, immobilization prior to HIT (OR 4.6, 95% CI 1.2-18.0; P = .026) and higher platelet counts before initiation of heparin therapy (OR 1.004, 95% CI 1.000-1.008; P = .046) were independently associated with the occurrence of thromboembolic events. CONCLUSIONS: Immobilization and a high platelet count (with a low effect size) are additional risk factors of thromboembolic complications in the course of HIT.


Assuntos
Heparina/efeitos adversos , Contagem de Plaquetas , Embolia Pulmonar/epidemiologia , Trombocitopenia/complicações , Trombose Venosa/epidemiologia , Idoso , Anticoagulantes/efeitos adversos , Procedimentos Cirúrgicos Cardiovasculares/efeitos adversos , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Farmacovigilância , Complicações Pós-Operatórias/prevenção & controle , Embolia Pulmonar/etiologia , Fatores de Risco , Trombocitopenia/induzido quimicamente , Trombose Venosa/etiologia
20.
Microsc Res Tech ; 79(11): 1105-1111, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27571574

RESUMO

Atomic force microscopy is not only a high-resolution imaging device but also a mechanical machine, which can be used either to indent or stretch (soft) biomaterials. Due to the statistical nature of such materials (i.e., hydrogels or polymers) hundreds of force-distance curves are required to describe their mechanical properties. In this manuscript, we present an automated system for polymer unfolding detection based on continuous wavelet analysis. We have tested the automated program on elastin, which is an important protein that provides elasticity to tissues and organs. Our results show that elastin changes its mechanical behavior in the presence of electrolytes. In particular, we show that NaCl has a different effect on the contour length than CaCl2 for similar unfolding forces. In addition, we provide the program in the supporting information for the researches facing such kind of problem.


Assuntos
Algoritmos , Microscopia de Força Atômica/métodos , Desdobramento de Proteína , Elastina/química , Elastina/metabolismo , Cloreto de Sódio/química , Termodinâmica , Análise de Ondaletas
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