ABSTRACT
Autonomous underwater vehicles (AUV) are seen as an emerging technology for maritime exploration but are still restricted by the availability of short range, accurate positioning methods necessary, e.g., when docking remote assets. Typical techniques used for high-accuracy positioning in indoor use case scenarios, such as systems using ultra-wide band radio signals (UWB), cannot be applied for underwater positioning because of the quick absorption of the positioning medium caused by the water. Acoustic and optic solutions for underwater positioning also face known problems, such as the multi-path effects, high propagation delay (acoustics), and environmental dependency. This paper presents an oscillating magnetic field-based indoor and underwater positioning system. Unlike those radio wave-based positioning modalities, the magnetic approach generates a bubble-formed magnetic field that will not be deformed by the environmental variation because of the very similar permeability of water and air. The proposed system achieves an underwater positioning mean accuracy of 13.3 cm in 2D and 19.0 cm in 3D with the multi-lateration positioning method and concludes the potential of the magnetic field-based positioning technique for underwater applications. A similar accuracy was also achieved for various indoor environments that were used to test the influence of cluttered environment and of cross environment. The low cost and power consumption system is scalable for extensive coverage area and could plug-and-play without pre-calibration.
ABSTRACT
Pediatric craniosynostosis (CS) surgery is frequently associated with extensive blood loss and transfusion requirements. The aim of the study was to evaluate the authors' institutional procedure with 2-surgeon approach and early transfusion strategy on blood loss and blood product transfusions in children undergoing craniofacial surgery. A retrospective analysis of medical records was performed of pediatric CS corrections during a 15-year period. Primary endpoint was blood loss and transfusion requirement during and the following 24âhours postoperatively. Linear regression analyses were performed of associations between intra and- postoperative blood loss and blood loss and weight. A total of 276 children (median 9 months) were included. Intraoperative blood loss was 22âmL/kg (14-33âmL/kg) and postoperatively 27âmL/kg (18-37âmL/kg), with no change during the study period. Intraoperative transfusions of red blood cell and plasma were 16âmL/kg (10-24âmL/kg) and postoperative 14âmL/kg (9-21âmL/kg). Postoperative red blood cell and plasma transfusions were 2âmL/kg (0-6âmL/kg) and of 0âmL/kg, respectively. Craniosynostosis type was related to blood loss (Pâ<â0.001). There was an association between intraoperative and postoperative blood loss (Pâ=â0.012) and intra- and postoperative blood loss and weight (Pâ=â0.002, Pâ=â<â0.001). Duration of surgery was 110âminutes (range 60-300âminutes).Pediatric CS surgery is associated with substantial intra- and postoperative blood loss and transfusion requirements, which did not change over a 15-year period. Blood loss was associated with type of CS. Intraoperative blood loss was correlated to postoperative blood loss and body weight.
Subject(s)
Blood Transfusion , Postoperative Hemorrhage , Adolescent , Blood Loss, Surgical , Child , Child, Preschool , Craniosynostoses/surgery , Humans , Infant , Retrospective StudiesABSTRACT
Background: In 2003, the World Federation for Medical Education (WFME) published the Trilogy of Global Standards for Quality Improvement of Medical Education, covering all three phases of education in medicine. The intention was to provide an instrument to be used by medical schools and responsible authorities in quality assurance and improvement of medical education. The standards were revised in 2015. Results: This paper reviews 29 published articles dealing with the practical use and analysis of the standards. 21 papers deal with basic medical education, six with postgraduate medical education and two with CPD. Conclusion: It is concluded that using the WFME standards can be a profitable endeavor with documented impact. Standards should be used as intended, i.e. as a template modified with local specifications.
Subject(s)
Education, Medical/standards , Quality Improvement/organization & administration , Schools, Medical/standards , Accreditation/standards , Clinical Competence , Curriculum/standards , Education, Medical, Graduate/standards , Guidelines as Topic , Humans , Quality Improvement/standardsABSTRACT
The pituitary hormone prolactin (PRL) has been implicated in tumourigenesis. Expression of PRL and its receptor (PRLR) was reported in human breast epithelium and breast cancer cells. It was suggested that PRL may act as an autocrine/paracrine growth factor. Here, we addressed the role of locally synthesised PRL in breast cancer. We analysed the expression of PRL in human breast cancer tumours using qPCR analysis and in situ hybridization (ISH). PRL mRNA expression was very low or undetectable in the majority of samples in three cDNA arrays representing samples from 144 breast cancer patients and in 13 of 14 breast cancer cell lines when analysed by qPCR. In accordance, PRL expression did not reach detectable levels in any of the 19 human breast carcinomas or 5 cell lines, which were analysed using a validated ISH protocol. Two T47D-derived breast cancer cell lines were stably transfected with PRL-expressing constructs. Conditioned medium from the T47D/PRL clones promoted proliferation of lactogen-dependent Nb2 cells and control T47D cells. Surprisingly, the PRL-producing clones themselves displayed a lower proliferation rate as compared to the control cells. Their PRLR protein level was reduced and the cells were no longer responsive to exogenous recombinant PRL. Taken together, these data strongly indicate that autocrine PRL signalling is unlikely to be a general mechanism promoting tumour growth in breast cancer patients.
Subject(s)
Autocrine Communication , Breast Neoplasms/metabolism , Prolactin/metabolism , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Carcinoma/genetics , Carcinoma/metabolism , Carcinoma/pathology , Cell Line, Tumor , Cell Proliferation , Female , Gene Expression , Gene Expression Regulation, Neoplastic , Humans , Immunohistochemistry , Prolactin/genetics , RNA, Messenger/genetics , Receptors, Prolactin/genetics , Receptors, Prolactin/metabolism , Signal TransductionABSTRACT
We report in vitro and in vivo data of new α-melanocyte-stimulating hormone (α-MSH) analogues which are N-terminal modified with a long chain fatty acid derivative. While keeping the pharmacophoric motif (d-Phe-Arg-Trp) fixed, we tried to improve selectivity and physicochemical parameters like solubility and stability of these analogues by replacing amino acids further away from the motif. Receptor specific changes in binding affinity to the melanocortin receptors were observed between the acetyl derivatives and the fatty acid analogues. Furthermore, amino acids at the N-terminal of α-MSH (Ser-Tyr-Ser) not considered to be part of the pharmacophore were found to have an influence on the MC4/MC1 receptor selectivity. While the acetyl analogues have an in vivo effect for around 7 h, the long chain fatty acid analogues have an effect up to 48 h in an acute feeding study in male Sprague-Dawley rats after a single subcutaneous administration.
Subject(s)
Anti-Obesity Agents/chemical synthesis , Receptor, Melanocortin, Type 4/agonists , alpha-MSH/analogs & derivatives , alpha-MSH/chemical synthesis , Animals , Anti-Obesity Agents/pharmacokinetics , Anti-Obesity Agents/pharmacology , Eating/drug effects , Fatty Acids/chemical synthesis , Fatty Acids/pharmacokinetics , Fatty Acids/pharmacology , Injections, Subcutaneous , Male , Rats , Rats, Sprague-Dawley , Solubility , Structure-Activity Relationship , alpha-MSH/pharmacokinetics , alpha-MSH/pharmacologyABSTRACT
Long-term stability of titanium implants are dependent on a variety of factors. Nanocoating with organic molecules is one of the methods used to improve osseointegration. Therefore, the aim of this study is to evaluate the in vitro effect of nanocoating with pectic rhamnogalacturonan-I (RG-I) on surface properties and osteoblasts response. Three different RG-Is from apple and lupin pectins were modified and coated on amino-functionalized tissue culture polystyrene plates (aminated TCPS). Surface properties were evaluated by scanning electron microscopy, contact angle measurement, atomic force microscopy, and X-ray photoelectron spectroscopy. The effects of nanocoating on proliferation, matrix formation and mineralization, and expression of genes (real-time PCR) related to osteoblast differentiation and activity were tested using human osteoblast-like SaOS-2 cells. It was shown that RG-I coatings affected the surface properties. All three RG-I induced bone matrix formation and mineralization, which was also supported by the finding that gene expression levels of alkaline phosphatase, osteocalcin, and collagen type-1 were increased in cells cultured on the RG-I coated surface, indicating a more differentiated osteoblastic phenotype. This makes RG-I coating a promising and novel candidate for nanocoatings of implants.
Subject(s)
Coated Materials, Biocompatible/chemistry , Nanostructures/chemistry , Osteoblasts/physiology , Pectins/chemistry , Prostheses and Implants , Animals , Cell Line , Coated Materials, Biocompatible/metabolism , Humans , Lupinus/chemistry , Malus/chemistry , Materials Testing , Microscopy, Atomic Force , Molecular Structure , Osseointegration , Osteoblasts/cytology , Pectins/metabolism , Photoelectron Spectroscopy , Surface PropertiesABSTRACT
Prolactin (PRL), a potent growth stimulator of the mammary epithelium, has been suggested to be a factor contributing to the development and progression of breast and prostate cancer. Several PRL receptor (PRLR) antagonists have been identified in the past decades, but their in vivo growth inhibitory potency was restricted by low receptor affinity, rendering them pharmacologically unattractive for clinical treatment. Thus, higher receptor affinity is essential for the development of improved PRLR antagonistic variants with improved in vivo potency. In this study, we generated Site 1 focused protein libraries of human G129R-PRL mutants and screened for those with increased affinity to the human PRLR. By combining the mutations with enhanced affinities for PRLR, we identified a novel G129R-PRL variant with mutations at Site 1 that render nearly 50-fold increase in the antagonistic potency in vitro.
Subject(s)
High-Throughput Screening Assays/methods , Human Growth Hormone/pharmacology , Prolactin/pharmacology , Receptors, Prolactin/antagonists & inhibitors , Breast Neoplasms/drug therapy , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Female , Human Growth Hormone/genetics , Humans , Male , Mutation , Prolactin/genetics , Prostatic Neoplasms/drug therapy , Prostatic Neoplasms/metabolism , Prostatic Neoplasms/pathology , Protein Binding , Receptors, Prolactin/genetics , Receptors, Prolactin/metabolism , Surface Plasmon Resonance/methodsABSTRACT
The pituitary hormone prolactin (PRL) plays an important role in mammary gland development. It was also suggested to contribute to breast cancer progression. In vivo data strongly supported a crucial role of PRL in promoting tumour growth; however, PRL demonstrated only a weak, if any, pro-proliferative effect on cancer cells in vitro. Several recent studies indicated that PRL action in vivo may be influenced by the hormonal milieu, e.g. other growth factors such as 17beta-oestradiol (E(2)). Here, we explored the potential interplay between PRL and E(2) in regulation of gene expression and cell growth. PRL alone induced either a weak or no proliferative response of T47D and BT-483 cells respectively, while it drastically enhanced cell proliferation in E(2)-stimulated cultures. Affymetrix microarray analysis revealed 12 genes to be regulated by E(2), while 57 genes were regulated by PRL in T47D cells. Most of the PRL-regulated genes (42/57) were not previously described as PRL target genes, e.g. WT1 and IER3. One hundred and five genes were found to be regulated upon PRL/E(2) co-treatment: highest up-regulation was found for EGR3, RUNX2, EGR1, MAFF, GLIPR1, IER3, SOCS3, WT1 and AREG. PRL and E(2) synergised to regulate EGR3, while multiple genes were regulated additively. These data show a novel interplay between PRL and E(2) to modulate gene regulation in breast cancer cells.
Subject(s)
Biomarkers, Tumor/genetics , Breast Neoplasms/genetics , Cell Proliferation , Estrogens/pharmacology , Gene Expression Regulation, Neoplastic/drug effects , Prolactin/pharmacology , Biomarkers, Tumor/metabolism , Blotting, Western , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Drug Synergism , Female , Gene Expression Profiling , Humans , Oligonucleotide Array Sequence Analysis , RNA, Messenger/genetics , Receptors, Estrogen/metabolism , Receptors, Prolactin/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Tumor Cells, CulturedABSTRACT
The pituitary hormone PRL is involved in tumorigenesis in rodents and humans. PRL promotes proliferation, survival and migration of cancer cells acting via the PRL receptor (PRLR). Aiming to perform a large-scale immunohistochemical (IHC) screening of human mammary carcinomas for PRLR expression, we evaluated the specificity of commercially available anti-human PRLR antibodies (B6.2, U5, PRLRi pAb, 1A2B1, 250448 and H-300). The latter three antibodies were found to specifically recognise PRLR. The relative PRLR expression level detected with these antibodies closely reflected the level of (125)I-PRL binding to the cell surface. The monoclonal antibody (mAb) 250448 was specific for the N-()glycosylated form of PRLR and blocked PRL binding and signalling. The PRLRi polyclonal antibody recognised cytokeratin-18. The mAb B6.2, previously used in a number of studies, was found to lack specificity for PRLR and to rather recognise a PRLR-associated protein. The mAb U5 raised against the rat PRLR did not cross-react with the human receptor. Only one mAb, 1A2B1, was found useful for detection of PRLR in IHC applications. This antibody recognised PRLR expressed in human breast cancer cell lines and decidual cells in tissue sections of human placenta. Screening of 160 mammary adenocarcinomas demonstrated significant immunoreactivity in only four tumours, indicating that PRLR is generally not strongly upregulated in human breast cancer. However, even a very low level of PRLR expression was found to be sufficient to mediate PRL responsiveness in breast cancer cell lines.
Subject(s)
Breast Neoplasms/genetics , Carcinoma/genetics , Receptors, Prolactin/genetics , Animals , Antibody Specificity , CHO Cells , Cricetinae , Cricetulus , Female , Gene Expression Regulation, Neoplastic , HT29 Cells , Humans , Prolactin/metabolism , Protein Binding , Receptors, Prolactin/immunology , Receptors, Prolactin/metabolism , Tissue Array Analysis , Tumor Cells, CulturedABSTRACT
The crystal structure of the complex between an N-terminally truncated G129R human prolactin (PRL) variant and the extracellular domain of the human prolactin receptor (PRLR) was determined at 2.5A resolution by x-ray crystallography. This structure represents the first experimental structure reported for a PRL variant bound to its cognate receptor. The binding of PRL variants to the PRLR extracellular domain was furthermore characterized by the solution state techniques, hydrogen exchange mass spectrometry, and NMR spectroscopy. Compared with the binding interface derived from mutagenesis studies, the structural data imply that the definition of PRL binding site 1 should be extended to include residues situated in the N-terminal part of loop 1 and in the C terminus. Comparison of the structure of the receptor-bound PRL variant with the structure reported for the unbound form of a similar analogue ( Jomain, J. B., Tallet, E., Broutin, I., Hoos, S., van Agthoven, J., Ducruix, A., Kelly, P. A., Kragelund, B. B., England, P., and Goffin, V. (2007) J. Biol. Chem. 282, 33118-33131 ) demonstrates that receptor-induced changes in the backbone of the four-helix bundle are subtle, whereas large scale rearrangements and structuring occur in the flexible N-terminal part of loop 1. Hydrogen exchange mass spectrometry data imply that the dynamics of the four-helix bundle in solution generally become stabilized upon receptor interaction at binding site 1.
Subject(s)
Peptides/chemistry , Prolactin/chemistry , Receptors, Prolactin/antagonists & inhibitors , Receptors, Prolactin/chemistry , Amino Acid Substitution , Binding Sites/genetics , Crystallography, X-Ray , Humans , Mutagenesis , Nuclear Magnetic Resonance, Biomolecular , Peptides/genetics , Peptides/metabolism , Prolactin/genetics , Prolactin/metabolism , Protein Structure, Quaternary , Protein Structure, Secondary , Protein Structure, Tertiary/genetics , Receptors, Prolactin/genetics , Receptors, Prolactin/metabolismABSTRACT
The remarkably high specificity of the coagulation proteases towards macromolecular substrates is provided by numerous interactions involving the catalytic groove and remote exosites. For FVIIa [activated FVII (Factor VII)], the principal initiator of coagulation via the extrinsic pathway, several exosites have been identified, whereas only little is known about the specificity dictated by the active-site architecture. In the present study, we have profiled the primary P4-P1 substrate specificity of FVIIa using positional scanning substrate combinatorial libraries and evaluated the role of the selective active site in defining specificity. Being a trypsin-like serine protease, FVIIa had P1 specificity exclusively towards arginine and lysine residues. In the S2 pocket, threonine, leucine, phenylalanine and valine residues were the most preferred amino acids. Both S3 and S4 appeared to be rather promiscuous, however, with some preference for aromatic amino acids at both positions. Interestingly, a significant degree of interdependence between the S3 and S4 was observed and, as a consequence, the optimal substrate for FVIIa could not be derived directly from a subsite-directed specificity screen. To evaluate the role of the active-site residues in defining specificity, a series of mutants of FVIIa were prepared at position 239 (position 99 in chymotrypsin), which is considered to be one of the most important residues for determining P2 specificity of the trypsin family members. This was confirmed for FVIIa by marked changes in primary substrate specificity and decreased rates of antithrombin III inhibition. Interestingly, these changes do not necessarily coincide with an altered ability to activate Factor X, demonstrating that inhibitor and macromolecular substrate selectivity may be engineered separately.
Subject(s)
Factor VIIa/antagonists & inhibitors , Factor VIIa/metabolism , Protein Engineering/methods , Amino Acid Sequence , Humans , Kinetics , Models, Molecular , Protein Conformation , Substrate SpecificityABSTRACT
The purpose of this study was to test whether the severity of the cranial phenotype in Muenke syndrome infants with unicoronal synostosis is greater than in infants with nonsyndromic unicoronal synostosis. A total of 23 infants were included in the study. All infants included in the study had a computed tomography (CT)-verified synostosis of the coronal suture. The patients were either placed into the "Muenke" group (n=11) or the "non-Muenke" control group (n=12) on the basis of a test for the P250R mutation in the FGFR3 gene. On the basis of CT scans, a three-dimensional surface model corresponding to bone was created for each individual. The sutures were inspected for synostosis, and the degree of synostosis was assessed. Increased digital markings were recorded for both groups. Craniofacial morphology was assessed quantitatively using bony landmarks and recording of the midsagittal surface of the calvaria, cranial base, and maxillary complex. Increased digital markings were more severe posteriorly in Muenke patients than in non-Muenke patients. The Muenke patients with unilateral coronal synostosis showed a somewhat more severe asymmetry in the anterior part of the skull than the non-Muenke patients. The study indicates differences with regard to severity of increased digital markings and craniofacial asymmetry between the infants with Muenke syndrome and the infants with nonsyndromic unilateral coronal synostosis.
Subject(s)
Cranial Sutures/pathology , Craniosynostoses/pathology , Facial Asymmetry/pathology , Amino Acid Substitution , Arginine , Chi-Square Distribution , Cranial Sutures/diagnostic imaging , Craniosynostoses/diagnostic imaging , Craniosynostoses/genetics , Facial Asymmetry/diagnostic imaging , Female , Humans , Imaging, Three-Dimensional , Infant , Male , Mutation, Missense , Proline , Receptor, Fibroblast Growth Factor, Type 3/genetics , Severity of Illness Index , Sex Ratio , Statistics, Nonparametric , Syndrome , Tomography, X-Ray ComputedABSTRACT
An outcome-based approach to medical education compared to a process/content orientation is currently being discussed intensively. In this article, the process and outcome interrelationship in medical education is discussed, with specific emphasis on the relation to the definition of standards in basic medical education. Perceptions of outcome have always been an integrated element of curricular planning. The present debate underlines the need for stronger focus on learning objectives and outcome assessment in many medical schools around the world. The need to maintain an integrated approach of process/content and outcome is underlined in this paper. A worry is expressed about the taxonomy of learning in pure outcome-based medical education, in which student assessment can be a major determinant for the learning process, leaving the control of the medical curriculum to medical examiners. Moreover, curricula which favour reductionism by stating everything in terms of instrumental outcomes or competences, do face a risk of lowering quality and do become a prey for political interference. Standards based on outcome alone rise unclarified problems in relationship to licensure requirements of medical doctors. It is argued that the alleged dichotomy between process/content and outcome seems artificial, and that formulation of standards in medical education must follow a comprehensive line in curricular planning.
Subject(s)
Clinical Competence/standards , Competency-Based Education/standards , Curriculum/standards , Education, Medical/standards , Program Evaluation/methods , Schools, Medical/organization & administration , Decision Making, Organizational , Educational Measurement , Humans , Learning , Models, Educational , Organizational Objectives , Problem-Based Learning/standards , Quality ControlABSTRACT
Human paracaspase has been predicted to be a member of the protein structural fold that encompasses protease clan CD. To determine whether paracaspase has catalytic activity we have expressed the region corresponding to the catalytic domain and used protease activity-based chemical probes to profile the putative active site. A leucine-based acyloxymethyl ketone probe that covalently labels cysteine proteases discloses a hydrophobic P 1 preference in the putative active site. The probe covalently labels Cys539, which is not the predicted catalytic site based on structural and sequence comparisons with other clan CD proteases. Using a combinatorial peptide substrate library approach we have been unable to detect amidolytic activity of paracaspase, implying that if it is a protease it must be very specific. We suggest a switch in the use of catalytic residues to generate an enzyme overlapping the canonical clan CD protease active site.
Subject(s)
Lymphoma, B-Cell, Marginal Zone/metabolism , Neoplasm Proteins/metabolism , Caspases , Catalytic Domain , Combinatorial Chemistry Techniques , Humans , Lymphoma, B-Cell, Marginal Zone/chemistry , Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein , Neoplasm Proteins/chemistry , Protein Conformation , Spectrometry, Mass, Matrix-Assisted Laser Desorption-IonizationABSTRACT
This study presents a novel method for rapid prototyping of polymer microsystems. The method is based on excimer laser ablation of a thermally and mechanically stable polymer, such as PEEK (poly-ether-ether-ketone). A negative of the desired microsystem is laser machined in PEEK, which can then be used directly for hot embossing or injection moulding of a series of prototypes. This approach is very rapid and considerably cheaper than more traditional approaches to toolmaking, while still performing well in terms of reproduction of tool dimensions. The reduction in time and cost for a master tool using this method opens up new possibilities for testing small series in the R&D phase of a microsystem. Finally, two particular applications of the technique are presented.
Subject(s)
Lasers , Microchemistry/instrumentation , Polymers/radiation effects , Benzophenones , Equipment Design/instrumentation , Equipment Design/methods , Ketones/chemistry , Ketones/radiation effects , Microchemistry/methods , Polyethylene Glycols/chemistry , Polyethylene Glycols/radiation effects , Polymers/chemistryABSTRACT
The Bologna Process designates the ongoing activities whereby the Ministers responsible for Higher Education in Europe attempt to change and harmonize fundamental aspects of all higher education in the many countries involved. This grand scheme is gaining momentum. The number of participating countries is increasing, more aspects of higher education are included and the number of activities and projects is growing. Medical education has so far been neglected in the process and awareness of the development at medical schools has been limited. The purpose of this paper is to introduce the Bologna Process, its background, objectives and main activities and to draw attention to some of the challenges medical education will probably have to face in the near future such as a structure based on two main cycles, undergraduate and graduate, a system of easily readable and comparable degrees and European cooperation in quality assurance including a system of accreditation, certification or comparable procedures. The position of medical education towards the Bologna Process is essential.