Lack of Norovirus Replication and Histo-Blood Group Antigen Expression in 3-Dimensional Intestinal Epithelial Cells

PubMed Central

Radtke, Andrea L.; Lay, Margarita K.; Hjelm, Brooke E.; Bolick, Alice N.; Sarker, Shameema S.; Atmar, Robert L.; Kingsley, David H.; Arntzen, Charles J.; Estes, Mary K.; Nickerson, Cheryl A.

2013-01-01

Noroviruses (NoVs) are a leading cause of gastroenteritis worldwide. An in vitro model for NoV replication remains elusive, making study of the virus difficult. A previous study, which used a 3-dimensional (3-D) intestinal model derived from INT-407 cells reported NoV replication and extensive cytopathic effects (CPE). Using the same 3-D model, but with highly purified Norwalk virus (NV), we attempted to replicate this study. Our results showed no evidence of NV replication by real-time PCR of viral RNA or by immunocytochemical detection of viral structural and nonstructural proteins. Immunocytochemical analysis of the 3-D cultures also showed no detectable presence of histo-blood group antigens that participate in NV binding and host tropism. To determine the potential cause of CPE observed in the previous study, we exposed 3-D cultures to lipopolysaccharide concentrations consistent with contaminated stool samples and observed morphologic features similar to CPE. We conclude that the 3-D INT-407 model does not support NV replication. PMID:23622517

ABH and Lewis histo-blood group antigens, a model for the meaning of oligosaccharide diversity in the face of a changing world.

PubMed

Marionneau, S; Cailleau-Thomas, A; Rocher, J; Le Moullac-Vaidye, B; Ruvoën, N; Clément, M; Le Pendu, J

2001-07-01

Antigens of the ABH and Lewis histo-blood group family have been known for a long time. Yet their biological meaning is still largely obscure. Based on the available knowledge about the genes involved in their biosynthesis and about their tissue distribution in humans and other mammals, we discuss here the selective forces that may maintain or propagate these oligosaccharide antigens. The ABO, alpha 1,2fucosyltransferase and alpha 1,3fucosyltransferase enzyme families have been generated by gene duplications. Members of these families contribute to biosynthesis of the antigens through epistatic interactions. We suggest that the highly polymorphic genes of each family provide intraspecies diversity that allows coping with diverse and rapidly evolving pathogens. In contrast, the genes of low frequency polymorphism are expected to play roles at the cellular level, although they may be dispensable at the individual level. In addition, some members of these three gene families are expected to be functionally redundant and may either provide a reservoir for additional diversity in the future or become inactivated. We also discuss the role of the ABH and Lewis histo-blood group antigens in pathologies such as cancer and cardiovascular diseases, but argue that it is merely incidental and devoid of evolutionary impact.

Dual-Extrusion 3D Printing of Anatomical Models for Education

ERIC Educational Resources Information Center

Smith, Michelle L.; Jones, James F. X.

2018-01-01

Two material 3D printing is becoming increasingly popular, inexpensive and accessible. In this paper, freely available printable files and dual extrusion fused deposition modelling were combined to create a number of functional anatomical models. To represent muscle and bone FilaFlex[superscript 3D] flexible filament and polylactic acid (PLA)…

Molecular Signatures Discriminating the Male and the Female Sexual Pathways in the Pearl Oyster Pinctada margaritifera

PubMed Central

Teaniniuraitemoana, Vaihiti; Huvet, Arnaud; Levy, Peva; Gaertner-Mazouni, Nabila; Gueguen, Yannick; Le Moullac, Gilles

2015-01-01

The genomics of economically important marine bivalves is studied to provide better understanding of the molecular mechanisms underlying their different reproductive strategies. The recently available gonad transcriptome of the black-lip pearl oyster Pinctada margaritifera is a novel and powerful resource to study these mechanisms in marine mollusks displaying hermaphroditic features. In this study, RNAseq quantification data of the P. margaritifera gonad transcriptome were analyzed to identify candidate genes in histologically-characterized gonad samples to provide molecular signatures of the female and male sexual pathway in this pearl oyster. Based on the RNAseq data set, stringent expression analysis identified 1,937 contigs that were differentially expressed between the gonad histological categories. From the hierarchical clustering analysis, a new reproduction model is proposed, based on a dual histo-molecular analytical approach. Nine candidate genes were identified as markers of the sexual pathway: 7 for the female pathway and 2 for the male one. Their mRNA levels were assayed by real-time PCR on a new set of gonadic samples. A clustering method revealed four principal expression patterns based on the relative gene expression ratio. A multivariate regression tree realized on these new samples and validated on the previously analyzed RNAseq samples showed that the sexual pathway of P. margaritifera can be predicted by a 3-gene-pair expression ratio model of 4 different genes: pmarg-43476, pmarg-foxl2, pmarg-54338 and pmarg-fem1-like. This 3-gene-pair expression ratio model strongly suggests only the implication of pmarg-foxl2 and pmarg-fem1-like in the sex inversion of P. margaritifera. This work provides the first histo-molecular model of P. margaritifera reproduction and a gene expression signature of its sexual pathway discriminating the male and female pathways. These represent useful tools for understanding and studying sex inversion, sex differentiation and sex determinism in this species and other related species for aquaculture purposes such as genetic selection programs. PMID:25815473

Correlation between lack of norovirus replication and histo-blood group antigen expression in 3D-intestinal epithelial cultures

USDA-ARS?s Scientific Manuscript database

Noroviruses (NoV) are a leading cause of gastroenteritis worldwide. An in vitro model for NoV replication remains elusive, making study of the virus difficult. One publication utilizing a 3-dimensional (3D) intestinal model derived from Int407 cells reported NoV replication and extensive cytopathi...

Predictions in the face of clinical reality: HistoCheck versus high-risk HLA allele mismatch combinations responsible for severe acute graft-versus-host disease.

PubMed

Askar, Medhat; Sobecks, Ronald; Morishima, Yasuo; Kawase, Takakazu; Nowacki, Amy; Makishima, Hideki; Maciejewski, Jaroslaw

2011-09-01

HLA polymorphism remains a major hurdle for hematopoietic stem cell transplantation (HSCT). In 2004, Elsner et al. proposed the HistoCheck Web-based tool to estimate the allogeneic potential between HLA-mismatched stem cell donor/recipient pairs expressed as a sequence similarity matching (SSM). SSM is based on the structure of HLA molecules and the functional similarity of amino acids. According to this algorithm, a high SSM score represents high dissimilarity between MHC molecules, resulting in a potentially more deleterious impact on stem cell transplant outcomes. We investigated the potential of SSM to predict high-risk HLA allele mismatch combinations responsible for severe acute graft-versus-host disease (aGVHD grades III and IV) published by Kawase et al., by comparing SSM in low- and high-risk combinations. SSM was calculated for allele mismatch combinations using the HistoCheck tool available on the Web (www.histocheck.org). We compared ranges and means of SSM among high-risk (15 combinations observed in 722 donor/recipient pairs) versus low-risk allele combinations (94 combinations in 3490 pairs). Simulation scenarios were created where the recipient's HLA allele was involved in multiple allele mismatch combinations with at least 1 high-risk and 1 low-risk mismatch combination. SSM values were then compared. The mean SSM for high- versus low-risk combinations were 2.39 and 2.90 at A, 1.06 and 2.53 at B, 16.60 and 14.99 at C, 4.02 and 3.81 at DRB1, and 7.47 and 6.94 at DPB1 loci, respectively. In simulation scenarios, no predictable SSM association with high- or low-risk combinations could be distinguished. No DQB1 combinations met the statistical criteria for our study. In conclusion, our analysis demonstrates that mean SSM scores were not significantly different, and SSM distributions were overlapping among high- and low-risk allele combinations within loci HLA-A, B, C, DRB1, and DPB1. This analysis does not support selecting donors for HSCT recipients based on low HistoCheck SSM scores. Copyright © 2011 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

ABO, Secretor and Lewis histo-blood group systems influence the digestive form of Chagas disease.

PubMed

Bernardo, Cássia Rubia; Camargo, Ana Vitória Silveira; Ronchi, Luís Sérgio; de Oliveira, Amanda Priscila; de Campos Júnior, Eumildo; Borim, Aldenis Albaneze; Brandão de Mattos, Cinara Cássia; Bestetti, Reinaldo Bulgarelli; de Mattos, Luiz Carlos

2016-11-01

Chagas disease, caused by Trypanosoma cruzi, can affect the heart, esophagus and colon. The reasons that some patients develop different clinical forms or remain asymptomatic are unclear. It is believed that tissue immunogenetic markers influence the tropism of T. cruzi for different organs. ABO, Secretor and Lewis histo-blood group systems express a variety of tissue carbohydrate antigens that influence the susceptibility or resistance to diseases. This study aimed to examine the association of ABO, secretor and Lewis histo-blood systems with the clinical forms of Chagas disease. We enrolled 339 consecutive adult patients with chronic Chagas disease regardless of gender (cardiomyopathy: n=154; megaesophagus: n=119; megacolon: n=66). The control group was composed by 488 healthy blood donors. IgG anti-T. cruzi antibodies were detected by ELISA. ABO and Lewis phenotypes were defined by standard hemagglutination tests. Secretor (FUT2) and Lewis (FUT3) genotypes, determined by Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), were used to infer the correct histo-blood group antigens expressed in the gastrointestinal tract. The proportions between groups were compared using the χ2 test with Yates correction and Fisher's exact test and the Odds Ratio (OR) and 95% Confidence Interval (95% CI) were calculated. An alpha error of 5% was considered significant with p-values <0.05 being corrected for multiple comparisons (pc). No statistically significant differences were found for the ABO (X 2 : 2.635; p-value=0.451), Secretor (X 2 : 0.056; p-value=0.812) or Lewis (X 2 : 2.092; p-value=0.351) histo-blood group phenotypes between patients and controls. However, B plus AB Secretor phenotypes were prevalent in pooled data from megaesophagus and megacolon patients (OR: 5.381; 95% CI: 1.230-23.529; p-value=0.011; pc=0.022) in comparison to A plus O Secretor phenotypes. The tissue antigen variability resulting from the combined action of ABO and Secretor histo-blood systems is associated with the digestive forms of Chagas disease. Copyright © 2016 Elsevier B.V. All rights reserved.

Anatomically accurate individual face modeling.

PubMed

Zhang, Yu; Prakash, Edmond C; Sung, Eric

2003-01-01

This paper presents a new 3D face model of a specific person constructed from the anatomical perspective. By exploiting the laser range data, a 3D facial mesh precisely representing the skin geometry is reconstructed. Based on the geometric facial mesh, we develop a deformable multi-layer skin model. It takes into account the nonlinear stress-strain relationship and dynamically simulates the non-homogenous behavior of the real skin. The face model also incorporates a set of anatomically-motivated facial muscle actuators and underlying skull structure. Lagrangian mechanics governs the facial motion dynamics, dictating the dynamic deformation of facial skin in response to the muscle contraction.

Interactions of donor sources and media influence the histo-morphological quality of full-thickness skin models.

PubMed

Lange, Julia; Weil, Frederik; Riegler, Christoph; Groeber, Florian; Rebhan, Silke; Kurdyn, Szymon; Alb, Miriam; Kneitz, Hermann; Gelbrich, Götz; Walles, Heike; Mielke, Stephan

2016-10-01

Human artificial skin models are increasingly employed as non-animal test platforms for research and medical purposes. However, the overall histopathological quality of such models may vary significantly. Therefore, the effects of manufacturing protocols and donor sources on the quality of skin models built-up from fibroblasts and keratinocytes derived from juvenile foreskins is studied. Histo-morphological parameters such as epidermal thickness, number of epidermal cell layers, dermal thickness, dermo-epidermal adhesion and absence of cellular nuclei in the corneal layer are obtained and scored accordingly. In total, 144 full-thickness skin models derived from 16 different donors, built-up in triplicates using three different culture conditions were successfully generated. In univariate analysis both media and donor age affected the quality of skin models significantly. Both parameters remained statistically significant in multivariate analyses. Performing general linear model analyses we could show that individual medium-donor-interactions influence the quality. These observations suggest that the optimal choice of media may differ from donor to donor and coincides with findings where significant inter-individual variations of growth rates in keratinocytes and fibroblasts have been described. Thus, the consideration of individual medium-donor-interactions may improve the overall quality of human organ models thereby forming a reproducible test platform for sophisticated clinical research. Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Application of kernel method in fluorescence molecular tomography

NASA Astrophysics Data System (ADS)

Zhao, Yue; Baikejiang, Reheman; Li, Changqing

2017-02-01

Reconstruction of fluorescence molecular tomography (FMT) is an ill-posed inverse problem. Anatomical guidance in the FMT reconstruction can improve FMT reconstruction efficiently. We have developed a kernel method to introduce the anatomical guidance into FMT robustly and easily. The kernel method is from machine learning for pattern analysis and is an efficient way to represent anatomical features. For the finite element method based FMT reconstruction, we calculate a kernel function for each finite element node from an anatomical image, such as a micro-CT image. Then the fluorophore concentration at each node is represented by a kernel coefficient vector and the corresponding kernel function. In the FMT forward model, we have a new system matrix by multiplying the sensitivity matrix with the kernel matrix. Thus, the kernel coefficient vector is the unknown to be reconstructed following a standard iterative reconstruction process. We convert the FMT reconstruction problem into the kernel coefficient reconstruction problem. The desired fluorophore concentration at each node can be calculated accordingly. Numerical simulation studies have demonstrated that the proposed kernel-based algorithm can improve the spatial resolution of the reconstructed FMT images. In the proposed kernel method, the anatomical guidance can be obtained directly from the anatomical image and is included in the forward modeling. One of the advantages is that we do not need to segment the anatomical image for the targets and background.

Optimized Heart Sampling and Systematic Evaluation of Cardiac Therapies in Mouse Models of Ischemic Injury: Assessment of Cardiac Remodeling and Semi-Automated Quantification of Myocardial Infarct Size.

PubMed

Valente, Mariana; Araújo, Ana; Esteves, Tiago; Laundos, Tiago L; Freire, Ana G; Quelhas, Pedro; Pinto-do-Ó, Perpétua; Nascimento, Diana S

2015-12-02

Cardiac therapies are commonly tested preclinically in small-animal models of myocardial infarction. Following functional evaluation, post-mortem histological analysis is essential to assess morphological and molecular alterations underlying the effectiveness of treatment. However, non-methodical and inadequate sampling of the left ventricle often leads to misinterpretations and variability, making direct study comparisons unreliable. Protocols are provided for representative sampling of the ischemic mouse heart followed by morphometric analysis of the left ventricle. Extending the use of this sampling to other types of in situ analysis is also illustrated through the assessment of neovascularization and cellular engraftment in a cell-based therapy setting. This is of interest to the general cardiovascular research community as it details methods for standardization and simplification of histo-morphometric evaluation of emergent heart therapies. © 2015 by John Wiley & Sons, Inc. Copyright © 2015 John Wiley & Sons, Inc.

The Computerized Anatomical Man (CAM) model

NASA Technical Reports Server (NTRS)

Billings, M. P.; Yucker, W. R.

1973-01-01

A computerized anatomical man (CAM) model, representing the most detailed and anatomically correct geometrical model of the human body yet prepared, has been developed for use in analyzing radiation dose distribution in man. This model of a 50-percentile standing USAF man comprises some 1100 unique geometric surfaces and some 2450 solid regions. Internal body geometry such as organs, voids, bones, and bone marrow are explicitly modeled. A computer program called CAMERA has also been developed for performing analyses with the model. Such analyses include tracing rays through the CAM geometry, placing results on magnetic tape in various forms, collapsing areal density data from ray tracing information to areal density distributions, preparing cross section views, etc. Numerous computer drawn cross sections through the CAM model are presented.

Construction of a 3-D anatomical model for teaching temporal lobectomy.

PubMed

de Ribaupierre, Sandrine; Wilson, Timothy D

2012-06-01

Although we live and work in 3 dimensional space, most of the anatomical teaching during medical school is done on 2-D (books, TV and computer screens, etc). 3-D spatial abilities are essential for a surgeon but teaching spatial skills in a non-threatening and safe educational environment is a much more difficult pedagogical task. Currently, initial anatomical knowledge formation or specific surgical anatomy techniques, are taught either in the OR itself, or in cadaveric labs; which means that the trainee has only limited exposure. 3-D computer models incorporated into virtual learning environments may provide an intermediate and key step in a blended learning approach for spatially challenging anatomical knowledge formation. Specific anatomical structures and their spatial orientation can be further clinically contextualized through demonstrations of surgical procedures in the 3-D digital environments. Recordings of digital models enable learner reviews, taking as much time as they want, stopping the demonstration, and/or exploring the model to understand the anatomical relation of each structure. We present here how a temporal lobectomy virtual model has been developed to aid residents and fellows conceptualization of the anatomical relationships between different cerebral structures during that procedure. We suggest in comparison to cadaveric dissection, such virtual models represent a cost effective pedagogical methodology providing excellent support for anatomical learning and surgical technique training. Copyright © 2012 Elsevier Ltd. All rights reserved.

Genogroup IV and VI Canine Noroviruses Interact with Histo-Blood Group Antigens

PubMed Central

Breiman, Adrien; le Pendu, Jacques

2014-01-01

ABSTRACT Human noroviruses (HuNV) are a significant cause of viral gastroenteritis in humans worldwide. HuNV attaches to cell surface carbohydrate structures known as histo-blood group antigens (HBGAs) prior to internalization, and HBGA polymorphism among human populations is closely linked to susceptibility to HuNV. Noroviruses are divided into 6 genogroups, with human strains grouped into genogroups I (GI), II, and IV. Canine norovirus (CNV) is a recently discovered pathogen in dogs, with strains classified into genogroups IV and VI. Whereas it is known that GI to GIII noroviruses bind to HBGAs and GV noroviruses recognize terminal sialic acid residues, the attachment factors for GIV and GVI noroviruses have not been reported. This study sought to determine the carbohydrate binding specificity of CNV and to compare it to the binding specificities of noroviruses from other genogroups. A panel of synthetic oligosaccharides were used to assess the binding specificity of CNV virus-like particles (VLPs) and identified α1,2-fucose as a key attachment factor. CNV VLP binding to canine saliva and tissue samples using enzyme-linked immunosorbent assays (ELISAs) and immunohistochemistry confirmed that α1,2-fucose-containing H and A antigens of the HBGA family were recognized by CNV. Phenotyping studies demonstrated expression of these antigens in a population of dogs. The virus-ligand interaction was further characterized using blockade studies, cell lines expressing HBGAs, and enzymatic removal of candidate carbohydrates from tissue sections. Recognition of HBGAs by CNV provides new insights into the evolution of noroviruses and raises concerns regarding the potential for zoonotic transmission of CNV to humans. IMPORTANCE Infections with human norovirus cause acute gastroenteritis in millions of people each year worldwide. Noroviruses can also affect nonhuman species and are divided into 6 different groups based on their capsid sequences. Human noroviruses in genogroups I and II interact with histo-blood group antigen carbohydrates, bovine noroviruses (genogroup III) interact with alpha-galactosidase (α-Gal) carbohydrates, and murine norovirus (genogroup V) recognizes sialic acids. The canine-specific strains of norovirus are grouped into genogroups IV and VI, and this study is the first to characterize which carbohydrate structures they can recognize. Using canine norovirus virus-like particles, this work shows that representative genogroup IV and VI viruses can interact with histo-blood group antigens. The binding specificity of canine noroviruses is therefore very similar to that of the human norovirus strains classified into genogroups I and II. This raises interesting questions about the evolution of noroviruses and suggests it may be possible for canine norovirus to infect humans. PMID:25008923

Finite-element modeling of the human neurocranium under functional anatomical aspects.

PubMed

Mall, G; Hubig, M; Koebke, J; Steinbuch, R

1997-08-01

Due to its functional significance the human skull plays an important role in biomechanical research. The present work describes a new Finite-Element model of the human neurocranium. The dry skull of a middle-aged woman served as a pattern. The model was developed using only the preprocessor (Mentat) of a commercial FE-system (Marc). Unlike that of other FE models of the human skull mentioned in the literature, the geometry in this model was designed according to functional anatomical findings. Functionally important morphological structures representing loci minoris resistentiae, especially the foramina and fissures of the skull base, were included in the model. The results of two linear static loadcase analyses in the region of the skull base underline the importance of modeling from the functional anatomical point of view.

Focal dose escalation for prostate cancer using 68Ga-HBED-CC PSMA PET/CT and MRI: a planning study based on histology reference.

PubMed

Zamboglou, Constantinos; Thomann, Benedikt; Koubar, Khodor; Bronsert, Peter; Krauss, Tobias; Rischke, Hans C; Sachpazidis, Ilias; Drendel, Vanessa; Salman, Nasr; Reichel, Kathrin; Jilg, Cordula A; Werner, Martin; Meyer, Philipp T; Bock, Michael; Baltas, Dimos; Grosu, Anca L

2018-05-02

Focal radiation therapy has gained of interest in treatment of patients with primary prostate cancer (PCa). The question of how to define the intraprostatic boost volume is still open. Previous studies showed that multiparametric MRI (mpMRI) or PSMA PET alone could be used for boost volume definition. However, other studies proposed that the combined usage of both has the highest sensitivity in detection of intraprostatic lesions. The aim of this study was to demonstrate the feasibility and to evaluate the tumour control probability (TCP) and normal tissue complication probability (NTCP) of radiation therapy dose painting using 68 Ga-HBED-CC PSMA PET/CT, mpMRI or the combination of both in primary PCa. Ten patients underwent PSMA PET/CT and mpMRI followed by prostatectomy. Three gross tumour volumes (GTVs) were created based on PET (GTV-PET), mpMRI (GTV-MRI) and the union of both (GTV-union). Two plans were generated for each GTV. Plan95 consisted of whole-prostate IMRT to 77 Gy in 35 fractions and a simultaneous boost to 95 Gy (Plan95 PET /Plan95 MRI /Plan95 union ). Plan80 consisted of whole-prostate IMRT to 76 Gy in 38 fractions and a simultaneous boost to 80 Gy (Plan80 PET /Plan80 MRI /Plan80 union ). TCPs were calculated for GTV-histo (TCP-histo), which was delineated based on PCa distribution in co-registered histology slices. NTCPs were assessed for bladder and rectum. Dose constraints of published protocols were reached in every treatment plan. Mean TCP-histo were 99.7% (range: 97%-100%) and 75.5% (range: 33%-95%) for Plan95 union and Plan80 union , respectively. Plan95 union had significantly higher TCP-histo values than Plan95 MRI (p = 0.008) and Plan95 PET (p = 0.008). Plan80 union had significantly higher TCP-histo values than Plan80 MRI (p = 0.012), but not than Plan80 PET (p = 0.472). Plan95 MRI had significantly lower NTCP-rectum than Plan95 union (p = 0.012). No significant differences in NTCP-rectum and NTCP-bladder were observed for all other plans (p > 0.05). IMRT dose escalation on GTVs based on mpMRI, PSMA PET/CT and the combination of both was feasible. Boosting GTV-union resulted in significantly higher TCP-histo with no or minimal increase of NTCPs compared to the other plans.

Assistance to neurosurgical planning: using a fuzzy spatial graph model of the brain for locating anatomical targets in MRI

NASA Astrophysics Data System (ADS)

Villéger, Alice; Ouchchane, Lemlih; Lemaire, Jean-Jacques; Boire, Jean-Yves

2007-03-01

Symptoms of neurodegenerative pathologies such as Parkinson's disease can be relieved through Deep Brain Stimulation. This neurosurgical technique relies on high precision positioning of electrodes in specific areas of the basal ganglia and the thalamus. These subcortical anatomical targets must be located at pre-operative stage, from a set of MRI acquired under stereotactic conditions. In order to assist surgical planning, we designed a semi-automated image analysis process for extracting anatomical areas of interest. Complementary information, provided by both patient's data and expert knowledge, is represented as fuzzy membership maps, which are then fused by means of suitable possibilistic operators in order to achieve the segmentation of targets. More specifically, theoretical prior knowledge on brain anatomy is modelled within a 'virtual atlas' organised as a spatial graph: a list of vertices linked by edges, where each vertex represents an anatomical structure of interest and contains relevant information such as tissue composition, whereas each edge represents a spatial relationship between two structures, such as their relative directions. The model is built using heterogeneous sources of information such as qualitative descriptions from the expert, or quantitative information from prelabelled images. For each patient, tissue membership maps are extracted from MR data through a classification step. Prior model and patient's data are then matched by using a research algorithm (or 'strategy') which simultaneously computes an estimation of the location of every structures. The method was tested on 10 clinical images, with promising results. Location and segmentation results were statistically assessed, opening perspectives for enhancements.

My Corporis Fabrica: an ontology-based tool for reasoning and querying on complex anatomical models

PubMed Central

2014-01-01

Background Multiple models of anatomy have been developed independently and for different purposes. In particular, 3D graphical models are specially useful for visualizing the different organs composing the human body, while ontologies such as FMA (Foundational Model of Anatomy) are symbolic models that provide a unified formal description of anatomy. Despite its comprehensive content concerning the anatomical structures, the lack of formal descriptions of anatomical functions in FMA limits its usage in many applications. In addition, the absence of connection between 3D models and anatomical ontologies makes it difficult and time-consuming to set up and access to the anatomical content of complex 3D objects. Results First, we provide a new ontology of anatomy called My Corporis Fabrica (MyCF), which conforms to FMA but extends it by making explicit how anatomical structures are composed, how they contribute to functions, and also how they can be related to 3D complex objects. Second, we have equipped MyCF with automatic reasoning capabilities that enable model checking and complex queries answering. We illustrate the added-value of such a declarative approach for interactive simulation and visualization as well as for teaching applications. Conclusions The novel vision of ontologies that we have developed in this paper enables a declarative assembly of different models to obtain composed models guaranteed to be anatomically valid while capturing the complexity of human anatomy. The main interest of this approach is its declarativity that makes possible for domain experts to enrich the knowledge base at any moment through simple editors without having to change the algorithmic machinery. This provides MyCF software environment a flexibility to process and add semantics on purpose for various applications that incorporate not only symbolic information but also 3D geometric models representing anatomical entities as well as other symbolic information like the anatomical functions. PMID:24936286

Anatomical models and wax Venuses: art masterpieces or scientific craft works?

PubMed Central

Ballestriero, R

2010-01-01

The art of wax modelling has an ancient origin but rose to prominence in 14th century Italy with the cult of votive artefacts. With the advent of Neoclassicism this art, now deemed repulsive, continued to survive in a scientific environment, where it flourished in the study of normal and pathological anatomy, obstetrics, zoology and botany. The achievement of having originated the creation of anatomical models in coloured wax must be ascribed to a joint effort undertaken by the Sicilian wax modeller Gaetano Giulio Zumbo and the French surgeon Guillaume Desnoues in the late 17th century. Interest in anatomical wax models spread throughout Europe during the 18th century, first in Bologna with Ercole Lelli, Giovanni Manzolini and Anna Morandi, and then in Florence with Felice Fontana and Clemente Susini. In England, the art of anatomical ceroplastics was brought to London from Florence by the sculptor Joseph Towne. Throughout the centuries many anatomical artists preferred this material due to the remarkable mimetic likeness obtained, far surpassing any other material. Independent of the material used, whether wood, wax or clay, anatomical models were always considered merely craft works confined to hospitals or faculties of medicine and have survived to this day only because of their scientific interest. Italian and English waxes are stylistically different but the remarkable results obtained by Susini and Towne, and the fact that some contemporary artists are again representing anatomical wax bodies in their works, makes the border that formerly separated art and craft indistinguishable. PMID:20002228

Anatomical models and wax Venuses: art masterpieces or scientific craft works?

PubMed

Ballestriero, R

2010-02-01

The art of wax modelling has an ancient origin but rose to prominence in 14th century Italy with the cult of votive artefacts. With the advent of Neoclassicism this art, now deemed repulsive, continued to survive in a scientific environment, where it flourished in the study of normal and pathological anatomy, obstetrics, zoology and botany. The achievement of having originated the creation of anatomical models in coloured wax must be ascribed to a joint effort undertaken by the Sicilian wax modeller Gaetano Giulio Zumbo and the French surgeon Guillaume Desnoues in the late 17th century. Interest in anatomical wax models spread throughout Europe during the 18th century, first in Bologna with Ercole Lelli, Giovanni Manzolini and Anna Morandi, and then in Florence with Felice Fontana and Clemente Susini. In England, the art of anatomical ceroplastics was brought to London from Florence by the sculptor Joseph Towne. Throughout the centuries many anatomical artists preferred this material due to the remarkable mimetic likeness obtained, far surpassing any other material. Independent of the material used, whether wood, wax or clay, anatomical models were always considered merely craft works confined to hospitals or faculties of medicine and have survived to this day only because of their scientific interest. Italian and English waxes are stylistically different but the remarkable results obtained by Susini and Towne, and the fact that some contemporary artists are again representing anatomical wax bodies in their works, makes the border that formerly separated art and craft indistinguishable.

Pathogenesis of Rushton bodies: A novel hypothesis.

PubMed

Sarode, Gargi S; Sarode, Sachin C; Tupkari, Jagdish V; Deshmukh, Revati; Patil, Shankargouda

2016-08-01

Rushton bodies (RBs) are one of the characteristic features seen in the epithelial lining of odontogenic cysts mainly radicular, dentigerous and odontogenic keratocyst. It has two different histo-morphological appearances; granular and homogeneous. Although widely investigated, the exact pathogenesis and histogenesis of RBs is still an enigma. Many hypotheses were made in the literature but none has explained conceivably the two histo-morphological appearances of RBs and their association with inflammation. In the present paper the various pathogenesis for the formation of RBs proposed till date are discussed along with proposal for a novel hypothesis. The given hypothesis is mainly related to inflammation and its effect on pore size of basement membrane of odontogenic cystic epithelium. It explains RBs association with inflammation as well as existence of two histo-morphological appearances. The proposed hypothesis also justifies the RB's presence inside the lining epithelium of odontogenic cyst despite its hematogenous origin. Future studies are advocated for isolating RBs using laser capture microdissection and subsequent biochemical, histochemical and electron microscopic analysis to substantiate the proposed hypothesis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Droplet-based microtumor model to assess cell-ECM interactions and drug resistance of gastric cancer cells.

PubMed

Jang, Minjeong; Koh, Ilkyoo; Lee, Seok Jae; Cheong, Jae-Ho; Kim, Pilnam

2017-01-27

Gastric cancer (GC) is a common aggressive malignant tumor with high incidence and mortality worldwide. GC is classified into intestinal and diffuse types according to the histo-morphological features. Because of distinctly different clinico-pathological features, new cancer therapy strategies and in vitro preclinical models for the two pathological variants of GC is necessary. Since extracellular matrix (ECM) influence the biological behavior of tumor cells, we hypothesized that GC might be more similarly modeled in 3D with matrix rather than in 2D. Herein, we developed a microfluidic-based a three-dimensional (3D) in vitro gastric cancer model, with subsequent drug resistance assay. AGS (intestinal type) and Hs746T (diffuse type) gastric cancer cell lines were encapsulated in collagen beads with high cellular viability. AGS exhibited an aggregation pattern with expansive growth, whereas Hs746T showed single-cell-level infiltration. Importantly, in microtumor models, epithelial-mesenchymal transition (EMT) and metastatic genes were upregulated, whereas E-cadherin was downregulated. Expression of ß-catenin was decreased in drug-resistant cells, and chemosensitivity toward the anticancer drug (5-FU) was observed in microtumors. These results suggest that in vitro microtumor models may represent a biologically relevant platform for studying gastric cancer cell biology and tumorigenesis, and for accelerating the development of novel therapeutic targets.

Realistic Anatomical Prostate Models for Surgical Skills Workshops Using Ballistic Gelatin for Nerve-Sparing Radical Prostatectomy and Fruit for Simple Prostatectomy

PubMed Central

Lindner, Uri; Klotz, Laurence

2011-01-01

Purpose Understanding of prostate anatomy has evolved as techniques have been refined and improved for radical prostatectomy (RP), particularly regarding the importance of the neurovascular bundles for erectile function. The objectives of this study were to develop inexpensive and simple but anatomically accurate prostate models not involving human or animal elements to teach the terminology and practical aspects of nerve-sparing RP and simple prostatectomy (SP). Materials and Methods The RP model used a Foley catheter with ballistics gelatin in the balloon and mesh fabric (neurovascular bundles) and balloons (prostatic fascial layers) on either side for the practice of inter- and intrafascial techniques. The SP model required only a ripe clementine, for which the skin represented compressed normal prostate, the pulp represented benign tissue, and the pith mimicked fibrous adhesions. A modification with a balloon through the fruit center acted as a "urethra." Results Both models were easily created and successfully represented the principles of anatomical nerve-sparing RP and SP. Both models were tested in workshops by urologists and residents of differing levels with positive feedback. Conclusions Low-fidelity models for prostate anatomy demonstration and surgical practice are feasible. They are inexpensive and simple to construct. Importantly, these models can be used for education on the practical aspects of nerve-sparing RP and SP. The models will require further validation as educational and competency tools, but as we move to an era in which human donors and animal experiments become less ethical and more difficult to complete, so too will low-fidelity models become more attractive. PMID:21379431

Composite Bone Models in Orthopaedic Surgery Research and Education

PubMed Central

Elfar, John; Stanbury, Spencer; Menorca, Ron Martin Garcia; Reed, Jeffrey Douglas

2014-01-01

Composite bone models are increasingly used in orthopaedic biomechanics research and surgical education—applications that traditionally relied on cadavers. Cadaver bones are suboptimal for myriad reasons, including issues of cost, availability, preservation, and inconsistency between specimens. Further, cadaver samples disproportionately represent the elderly, whose bone quality may not be representative of the greater orthopaedic population. The current fourth-generation composite bone models provide an accurate reproduction of the biomechanical properties of human bone when placed under bending, axial, and torsional loads. The combination of glass fiber and epoxy resin components into a single phase has enabled manufacturing by injection molding. The high anatomic fidelity of the cadaver-based molds and negligible shrinkage properties of the epoxy resin results in a process that allows for excellent definition of anatomic detail in the cortical wall and optimized consistency of features between models. Recent biomechanical studies of composites have validated their use as a suitable substitute for cadaver specimens. PMID:24486757

Composite bone models in orthopaedic surgery research and education.

PubMed

Elfar, John; Menorca, Ron Martin Garcia; Reed, Jeffrey Douglas; Stanbury, Spencer

2014-02-01

Composite bone models are increasingly used in orthopaedic biomechanics research and surgical education-applications that traditionally relied on cadavers. Cadaver bones are suboptimal for many reasons, including issues of cost, availability, preservation, and inconsistency between specimens. Further, cadaver samples disproportionately represent the elderly, whose bone quality may not be representative of the greater orthopaedic population. The current fourth-generation composite bone models provide an accurate reproduction of the biomechanical properties of human bone when placed under bending, axial, and torsional loads. The combination of glass fiber and epoxy resin components into a single phase has enabled manufacturing by injection molding. The high level of anatomic fidelity of the cadaver-based molds and negligible shrinkage properties of the epoxy resin results in a process that allows for excellent definition of anatomic detail in the cortical wall and optimized consistency of features between models. Recent biomechanical studies of composites have validated their use as a suitable substitute for cadaver specimens.

Ballistics and anatomical modelling - A review.

PubMed

Humphrey, Caitlin; Kumaratilake, Jaliya

2016-11-01

Ballistics is the study of a projectiles motion and can be broken down into four stages: internal, intermediate, external and terminal ballistics. The study of the effects a projectile has on a living tissue is referred to as wound ballistics and falls within terminal ballistics. To understand the effects a projectile has on living tissues the mechanisms of wounding need to be understood. These include the permanent and temporary cavities, energy, yawing, tumbling and fragmenting. Much ballistics research has been conducted including using cadavers, animal models and simulants such as ballistics ordnance gelatine. Further research is being conducted into developing anatomical, 3D, experimental and computational models. However, these models need to accurately represent the human body and its heterogeneous nature which involves understanding the biomechanical properties of the different tissues and organs. Further research is needed to accurately represent the human tissues with simulants and is slowly being conducted. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Role of docosahexaenoic acid treatment in improving liver histology in pediatric nonalcoholic fatty liver disease.

PubMed

Nobili, Valerio; Carpino, Guido; Alisi, Anna; De Vito, Rita; Franchitto, Antonio; Alpini, Gianfranco; Onori, Paolo; Gaudio, Eugenio

2014-01-01

Nonalcoholic fatty liver disease (NAFLD) is one of the most important causes of liver-related morbidity and mortality in children. Recently, we have reported the effects of docosahexaenoic acid (DHA), the major dietary long-chain polyunsaturated fatty acids, in children with NAFLD. DHA exerts a potent anti-inflammatory activity through the G protein-coupled receptor (GPR)120. Our aim was to investigate in pediatric NAFLD the mechanisms underlying the effects of DHA administration on histo-pathological aspects, GPR120 expression, hepatic progenitor cell activation and macrophage pool. 20 children with untreated NAFLD were included. Children were treated with DHA for 18 months. Liver biopsies before and after the treatment were analyzed. Hepatic progenitor cell activation, macrophage pool and GPR120 expression were evaluated and correlated with clinical and histo-pathological parameters. GPR120 was expressed by hepatocytes, liver macrophages, and hepatic progenitor cells. After DHA treatment, the following modifications were present: i) the improvement of histo-pathological parameters such as NAFLD activity score, ballooning, and steatosis; ii) the reduction of hepatic progenitor cell activation in correlation with histo-pathological parameters; iii) the reduction of the number of inflammatory macrophages; iv) the increase of GPR120 expression in hepatocytes; v) the reduction of serine-311-phosphorylated nuclear factor kappa B (NF-κB) nuclear translocation in hepatocytes and macrophages in correlation with serum inflammatory cytokines. DHA could modulate hepatic progenitor cell activation, hepatocyte survival and macrophage polarization through the interaction with GPR120 and NF-κB repression. In this scenario, the modulation of GPR120 exploits a novel crucial role in the regulation of the cell-to-cell cross-talk that drives inflammatory response, hepatic progenitor cell activation and hepatocyte survival.

Subject-specific longitudinal shape analysis by coupling spatiotemporal shape modeling with medial analysis

NASA Astrophysics Data System (ADS)

Hong, Sungmin; Fishbaugh, James; Rezanejad, Morteza; Siddiqi, Kaleem; Johnson, Hans; Paulsen, Jane; Kim, Eun Young; Gerig, Guido

2017-02-01

Modeling subject-specific shape change is one of the most important challenges in longitudinal shape analysis of disease progression. Whereas anatomical change over time can be a function of normal aging, anatomy can also be impacted by disease related degeneration. Anatomical shape change may also be affected by structural changes from neighboring shapes, which may cause non-linear variations in pose. In this paper, we propose a framework to analyze disease related shape changes by coupling extrinsic modeling of the ambient anatomical space via spatiotemporal deformations with intrinsic shape properties from medial surface analysis. We compare intrinsic shape properties of a subject-specific shape trajectory to a normative 4D shape atlas representing normal aging to isolate shape changes related to disease. The spatiotemporal shape modeling establishes inter/intra subject anatomical correspondence, which in turn enables comparisons between subjects and the 4D shape atlas, and also quantitative analysis of disease related shape change. The medial surface analysis captures intrinsic shape properties related to local patterns of deformation. The proposed framework jointly models extrinsic longitudinal shape changes in the ambient anatomical space, as well as intrinsic shape properties to give localized measurements of degeneration. Six high risk subjects and six controls are randomly sampled from a Huntington's disease image database for qualitative and quantitative comparison.

Numeric and symbolic knowledge representation of cerebral cortex anatomy: methods and preliminary results.

PubMed

Dameron, O; Gibaud, B; Morandi, X

2004-06-01

The human cerebral cortex anatomy describes the brain organization at the scale of gyri and sulci. It is used as landmarks for neurosurgery as well as localization support for functional data analysis or inter-subject data comparison. Existing models of the cortex anatomy either rely on image labeling but fail to represent variability and structural properties or rely on a conceptual model but miss the inner 3D nature and relations of anatomical structures. This study was therefore conducted to propose a model of sulco-gyral anatomy for the healthy human brain. We hypothesized that both numeric knowledge (i.e., image-based) and symbolic knowledge (i.e., concept-based) have to be represented and coordinated. In addition, the representation of this knowledge should be application-independent in order to be usable in various contexts. Therefore, we devised a symbolic model describing specialization, composition and spatial organization of cortical anatomical structures. We also collected numeric knowledge such as 3D models of shape and shape variation about cortical anatomical structures. For each numeric piece of knowledge, a companion file describes the concept it refers to and the nature of the relationship. Demonstration software performs a mapping between the numeric and the symbolic aspects for browsing the knowledge base.

Comparison of 68Ga-HBED-CC PSMA-PET/CT and multiparametric MRI for gross tumour volume detection in patients with primary prostate cancer based on slice by slice comparison with histopathology

PubMed Central

Zamboglou, Constantinos; Drendel, Vanessa; Jilg, Cordula A.; Rischke, Hans C.; Beck, Teresa I.; Schultze-Seemann, Wolfgang; Krauss, Tobias; Mix, Michael; Schiller, Florian; Wetterauer, Ulrich; Werner, Martin; Langer, Mathias; Bock, Michael; Meyer, Philipp T.; Grosu, Anca L.

2017-01-01

Purpose: The exact detection and delineation of the intraprostatic tumour burden is crucial for treatment planning in primary prostate cancer (PCa). We compared 68Ga-HBED-CC-PSMA PET/CT with multiparametric MRI (mpMRI) for diagnosis and tumour delineation in patients with primary PCa based on slice by slice correlation with histopathological reference material. Methodology: Seven patients with histopathologically proven primary PCa underwent 68Ga-HBED-CC-PSMA PET/CT and MRI followed by radical prostatectomy. Resected prostates were scanned by ex-vivo CT in a special localizer and prepared for histopathology. Invasive PCa was delineated on a HE stained histologic tissue slide and matched to ex-vivo CT to obtain gross tumor volume (GTV-)histo. Ex-vivo CT including GTV-histo and MRI data were matched to in-vivo CT(PET). Consensus contours based on MRI (GTV-MRI), PSMA PET (GTV-PET) or the combination of both (GTV-union/-intersection) were created. In each in-vivo CT slice the prostate was separated into 4 equal segments and sensitivity and specificity for PSMA PET and mpMRI were assessed by comparison with histological reference material. Furthermore, the spatial overlap between GTV-histo and GTV-PET/-MRI and the Sørensen-Dice coefficient (DSC) were calculated. In the case of multifocal PCa (4/7 patients), SUV values (PSMA PET) and ADC-values (diffusion weighted MRI) were obtained for each lesion. Results: PSMA PET and mpMRI detected PCa in all patients. GTV-histo was detected in 225 of 340 segments (66.2%). Sensitivity and specificity for GTV-PET, GTV-MRI, GTV-union and GTV-intersection were 75% and 87%, 70% and 82%, 82% and 67%, 55% and 99%, respectively. GTV-histo had on average the highest overlap with GTV-union (57±22%), which was significantly higher than overlap with GTV-MRI (p=0.016) and GTV-PET (p=0.016), respectively. The mean DSC for GTV-union, GTV-PET and GTV-MRI was 0.51 (±0.18), 0.45 (±0.17) and 0.48 (±0.19), respectively. In every patient with multifocal PCa there was one lesion which had both the highest SUV and the lowest ADC-value (mean and max). Conclusion: In a slice by slice analysis with histopathology, 68Ga-HBED-CC-PSMA PET/CT and mpMRI showed high sensitivity and specificity in detection of primary PCa. A combination of both methods performed even better in terms of sensitivity (GTV-union) and specificity (GTV-intersection). A moderate to good spatial overlap with GTV-histo was observed for PSMA PET/CT and mpMRI alone which was significantly improved by GTV-union. Further studies are warranted to analyse the impact of these preliminary findings for diagnostic (multimodal guided TRUS biopsy) and therapeutic (focal therapy) strategies in primary PCa. PMID:28042330

The anatomy of the coracohumeral ligament and its relation to the subscapularis muscle.

PubMed

Arai, Ryuzo; Nimura, Akimoto; Yamaguchi, Kumiko; Yoshimura, Hideya; Sugaya, Hiroyuki; Saji, Takahiko; Matsuda, Shuichi; Akita, Keiichi

2014-10-01

Only a few reports describe the extension of the coracohumeral ligament to the subscapularis muscle. The purposes of this study were to histo-anatomically examine the structure between the ligament and subscapularis and to discuss the function of the ligament. Nineteen intact embalmed shoulders were used. In 9 shoulders, the expansion of the ligament was anatomically observed, and in 6 of these 9, the muscular tissue of the supraspinatus and subscapularis was removed to carefully examine the attachments to the tendons of these muscles. Five shoulders were frozen and sagittally sectioned into 3-mm-thick slices. After observation, histologic analysis was performed on 3 of these shoulders. In the remaining 5 shoulders, the coracoid process was harvested to investigate the ligament origin. The coracohumeral ligament originated from the horizontal limb and base of the coracoid process and enveloped the cranial part of the subscapularis muscle. The superficial layer of the ligament covered a broad area of the anterior surface of the muscle. Laterally, it protruded between the long head of the biceps tendon and subscapularis and attached to the tendinous floor, which extended from the subscapularis insertion. Histologically, the ligament consisted of irregular and sparse fibers abundant in type III collagen. The coracohumeral ligament envelops the whole subscapularis muscle and insertion and seems to function as a kind of holder for the subscapularis and supraspinatus muscles. The ligament is composed of irregular and sparse fibers and contains relatively rich type III collagen, which would suggest flexibility. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Joint brain connectivity estimation from diffusion and functional MRI data

NASA Astrophysics Data System (ADS)

Chu, Shu-Hsien; Lenglet, Christophe; Parhi, Keshab K.

2015-03-01

Estimating brain wiring patterns is critical to better understand the brain organization and function. Anatomical brain connectivity models axonal pathways, while the functional brain connectivity characterizes the statistical dependencies and correlation between the activities of various brain regions. The synchronization of brain activity can be inferred through the variation of blood-oxygen-level dependent (BOLD) signal from functional MRI (fMRI) and the neural connections can be estimated using tractography from diffusion MRI (dMRI). Functional connections between brain regions are supported by anatomical connections, and the synchronization of brain activities arises through sharing of information in the form of electro-chemical signals on axon pathways. Jointly modeling fMRI and dMRI data may improve the accuracy in constructing anatomical connectivity as well as functional connectivity. Such an approach may lead to novel multimodal biomarkers potentially able to better capture functional and anatomical connectivity variations. We present a novel brain network model which jointly models the dMRI and fMRI data to improve the anatomical connectivity estimation and extract the anatomical subnetworks associated with specific functional modes by constraining the anatomical connections as structural supports to the functional connections. The key idea is similar to a multi-commodity flow optimization problem that minimizes the cost or maximizes the efficiency for flow configuration and simultaneously fulfills the supply-demand constraint for each commodity. In the proposed network, the nodes represent the grey matter (GM) regions providing brain functionality, and the links represent white matter (WM) fiber bundles connecting those regions and delivering information. The commodities can be thought of as the information corresponding to brain activity patterns as obtained for instance by independent component analysis (ICA) of fMRI data. The concept of information flow is introduced and used to model the propagation of information between GM areas through WM fiber bundles. The link capacity, i.e., ability to transfer information, is characterized by the relative strength of fiber bundles, e.g., fiber count gathered from the tractography of dMRI data. The node information demand is considered to be proportional to the correlation between neural activity at various cortical areas involved in a particular functional mode (e.g. visual, motor, etc.). These two properties lead to the link capacity and node demand constraints in the proposed model. Moreover, the information flow of a link cannot exceed the demand from either end node. This is captured by the feasibility constraints. Two different cost functions are considered in the optimization formulation in this paper. The first cost function, the reciprocal of fiber strength represents the unit cost for information passing through the link. In the second cost function, a min-max (minimizing the maximal link load) approach is used to balance the usage of each link. Optimizing the first cost function selects the pathway with strongest fiber strength for information propagation. In the second case, the optimization procedure finds all the possible propagation pathways and allocates the flow proportionally to their strength. Additionally, a penalty term is incorporated with both the cost functions to capture the possible missing and weak anatomical connections. With this set of constraints and the proposed cost functions, solving the network optimization problem recovers missing and weak anatomical connections supported by the functional information and provides the functional-associated anatomical subnetworks. Feasibility is demonstrated using realistic diffusion and functional MRI phantom data. It is shown that the proposed model recovers the maximum number of true connections, with fewest number of false connections when compared with the connectivity derived from a joint probabilistic model using the expectation-maximization (EM) algorithm presented in a prior work. We also apply the proposed method to data provided by the Human Connectome Project (HCP).

Modelling tendon excursions and moment arms of the finger flexors: anatomic fidelity versus function.

PubMed

Kociolek, Aaron M; Keir, Peter J

2011-07-07

A detailed musculoskeletal model of the human hand is needed to investigate the pathomechanics of tendon disorders and carpal tunnel syndrome. The purpose of this study was to develop a biomechanical model with realistic flexor tendon excursions and moment arms. An existing upper extremity model served as a starting point, which included programmed movement of the index finger. Movement capabilities were added for the other fingers. Metacarpophalangeal articulations were modelled as universal joints to simulate flexion/extension and abduction/adduction while interphalangeal articulations used hinges to represent flexion. Flexor tendon paths were modelled using two approaches. The first method constrained tendons with control points, representing annular pulleys. The second technique used wrap objects at the joints as tendon constraints. Both control point and joint wrap models were iteratively adjusted to coincide with tendon excursions and moment arms from a anthropometric regression model using inputs for a 50th percentile male. Tendon excursions from the joint wrap method best matched the regression model even though anatomic features of the tendon paths were not preserved (absolute differences: mean<0.33 mm, peak<0.74 mm). The joint wrap model also produced similar moment arms to the regression (absolute differences: mean<0.63 mm, peak<1.58 mm). When a scaling algorithm was used to test anthropometrics, the scaled joint wrap models better matched the regression than the scaled control point models. Detailed patient-specific anatomical data will improve model outcomes for clinical use; however, population studies may benefit from simplified geometry, especially with anthropometric scaling. Copyright © 2011 Elsevier Ltd. All rights reserved.

Induction of Human Blood Group A Antigen Expression on Mouse Cells, Using Lentiviral Gene Transduction

PubMed Central

Fan, Xiaohu; Lang, Haili; Zhou, Xianpei; Zhang, Li; Yin, Rong; Maciejko, Jessica; Giannitsos, Vasiliki; Motyka, Bruce; Medin, Jeffrey A.; Platt, Jeffrey L.

2010-01-01

Abstract The ABO histo-blood group system is the most important antigen system in transplantation medicine, yet no small animal model of the ABO system exists. To determine the feasibility of developing a murine model, we previously subcloned the human α-1,2-fucosyltransferase (H-transferase, EC 2.4.1.69) cDNA and the human α-1,3-N-acetylgalactosaminyltransferase (A-transferase, EC 2.4.1.40) cDNA into lentiviral vectors to study their ability to induce human histo-blood group A antigen expression on mouse cells. Herein we investigated the optimal conditions for human A and H antigen expression in murine cells. We determined that transduction of a bicistronic lentiviral vector (LvEF1-AH-trs) resulted in the expression of A antigen in a mouse endothelial cell line. We also studied the in vivo utility of this vector to induce human A antigen expression in mouse liver. After intrahepatic injection of LvEF1-AH-trs, A antigen expression was observed on hepatocytes as detected by immunohistochemistry and real-time RT-PCR. In human group A erythrocyte-sensitized mice, A antigen expression in the liver was associated with tissue damage, and deposition of antibody and complement. These results suggest that this gene transfer strategy can be used to simulate the human ABO blood group system in a murine model. This model will facilitate progress in the development of interventions for ABO-incompatible transplantation and transfusion scenarios, which are difficult to develop in clinical or large animal settings. PMID:20163247

AutoStitcher: An Automated Program for Efficient and Robust Reconstruction of Digitized Whole Histological Sections from Tissue Fragments

NASA Astrophysics Data System (ADS)

Penzias, Gregory; Janowczyk, Andrew; Singanamalli, Asha; Rusu, Mirabela; Shih, Natalie; Feldman, Michael; Stricker, Phillip D.; Delprado, Warick; Tiwari, Sarita; Böhm, Maret; Haynes, Anne-Maree; Ponsky, Lee; Viswanath, Satish; Madabhushi, Anant

2016-07-01

In applications involving large tissue specimens that have been sectioned into smaller tissue fragments, manual reconstruction of a “pseudo whole-mount” histological section (PWMHS) can facilitate (a) pathological disease annotation, and (b) image registration and correlation with radiological images. We have previously presented a program called HistoStitcher, which allows for more efficient manual reconstruction than general purpose image editing tools (such as Photoshop). However HistoStitcher is still manual and hence can be laborious and subjective, especially when doing large cohort studies. In this work we present AutoStitcher, a novel automated algorithm for reconstructing PWMHSs from digitized tissue fragments. AutoStitcher reconstructs (“stitches”) a PWMHS from a set of 4 fragments by optimizing a novel cost function that is domain-inspired to ensure (i) alignment of similar tissue regions, and (ii) contiguity of the prostate boundary. The algorithm achieves computational efficiency by performing reconstruction in a multi-resolution hierarchy. Automated PWMHS reconstruction results (via AutoStitcher) were quantitatively and qualitatively compared to manual reconstructions obtained via HistoStitcher for 113 prostate pathology sections. Distances between corresponding fiducials placed on each of the automated and manual reconstruction results were between 2.7%-3.2%, reflecting their excellent visual similarity.

An illustrated anatomical ontology of the developing mouse lower urogenital tract

PubMed Central

Georgas, Kylie M.; Armstrong, Jane; Keast, Janet R.; Larkins, Christine E.; McHugh, Kirk M.; Southard-Smith, E. Michelle; Cohn, Martin J.; Batourina, Ekatherina; Dan, Hanbin; Schneider, Kerry; Buehler, Dennis P.; Wiese, Carrie B.; Brennan, Jane; Davies, Jamie A.; Harding, Simon D.; Baldock, Richard A.; Little, Melissa H.; Vezina, Chad M.; Mendelsohn, Cathy

2015-01-01

Malformation of the urogenital tract represents a considerable paediatric burden, with many defects affecting the lower urinary tract (LUT), genital tubercle and associated structures. Understanding the molecular basis of such defects frequently draws on murine models. However, human anatomical terms do not always superimpose on the mouse, and the lack of accurate and standardised nomenclature is hampering the utility of such animal models. We previously developed an anatomical ontology for the murine urogenital system. Here, we present a comprehensive update of this ontology pertaining to mouse LUT, genital tubercle and associated reproductive structures (E10.5 to adult). Ontology changes were based on recently published insights into the cellular and gross anatomy of these structures, and on new analyses of epithelial cell types present in the pelvic urethra and regions of the bladder. Ontology changes include new structures, tissue layers and cell types within the LUT, external genitalia and lower reproductive structures. Representative illustrations, detailed text descriptions and molecular markers that selectively label muscle, nerves/ganglia and epithelia of the lower urogenital system are also presented. The revised ontology will be an important tool for researchers studying urogenital development/malformation in mouse models and will improve our capacity to appropriately interpret these with respect to the human situation. PMID:25968320

An illustrated anatomical ontology of the developing mouse lower urogenital tract.

PubMed

Georgas, Kylie M; Armstrong, Jane; Keast, Janet R; Larkins, Christine E; McHugh, Kirk M; Southard-Smith, E Michelle; Cohn, Martin J; Batourina, Ekatherina; Dan, Hanbin; Schneider, Kerry; Buehler, Dennis P; Wiese, Carrie B; Brennan, Jane; Davies, Jamie A; Harding, Simon D; Baldock, Richard A; Little, Melissa H; Vezina, Chad M; Mendelsohn, Cathy

2015-05-15

Malformation of the urogenital tract represents a considerable paediatric burden, with many defects affecting the lower urinary tract (LUT), genital tubercle and associated structures. Understanding the molecular basis of such defects frequently draws on murine models. However, human anatomical terms do not always superimpose on the mouse, and the lack of accurate and standardised nomenclature is hampering the utility of such animal models. We previously developed an anatomical ontology for the murine urogenital system. Here, we present a comprehensive update of this ontology pertaining to mouse LUT, genital tubercle and associated reproductive structures (E10.5 to adult). Ontology changes were based on recently published insights into the cellular and gross anatomy of these structures, and on new analyses of epithelial cell types present in the pelvic urethra and regions of the bladder. Ontology changes include new structures, tissue layers and cell types within the LUT, external genitalia and lower reproductive structures. Representative illustrations, detailed text descriptions and molecular markers that selectively label muscle, nerves/ganglia and epithelia of the lower urogenital system are also presented. The revised ontology will be an important tool for researchers studying urogenital development/malformation in mouse models and will improve our capacity to appropriately interpret these with respect to the human situation. © 2015. Published by The Company of Biologists Ltd.

Mid-twentieth-century anatomical transparencies and the depiction of three-dimensional form.

PubMed

Wall, Shelley

2010-11-01

Before the advent of digital visualization, the "anatomical transparency"--layered images of organ systems, printed on a transparent medium--flourished in the mid-twentieth century as an interactive means to represent complex anatomical relationships to medical professionals and lay audiences. This article introduces the transparency work of medical illustrators Gladys McHugh and Ernest W. Beck, situating it in the historical context of strategies to represent three-dimensional anatomical relationships using print media.

[Not Available].

PubMed

Richter, J

2000-09-01

The investigation of Lenin's brain by the German neurobiologist Oskar Vogt from Berlin and his Russian collaborators in Moscow is one of the most exciting and simultaneously oddest chapters in the history of medicine. With the bizarre claim to be able to detect the material substrate of genius it provoked as much unrealistic expectations in the public as strong criticism by the scientific community of brain researchers. The present paper deals in a brief survey with the history of collecting and measuring the brains of famous persons in general and particularly with the historical, political and social circumstances of the performed investigation of Lenin's brain. In this connection the epistemological and technical prerequisites of architectonical brain research and its means of the topographical representation of complex histo-anatomical and physiological differences in the brain cortex are shortly discussed. The opening of Russian archives after the socio-economic turn of the year 1991 brought up new background facts in Lenin's pathobiography; together with the sources from German archives a rather extensive reconstruction of the historical events between Lenin's death in 1924 and the final report of the Moscow Brain Research Institute (Institute Mozga) to the Politburo of the Russian Communist Party (Bolsheviki) in 1936 is possible now.

3D scanning and printing skeletal tissues for anatomy education.

PubMed

Thomas, Daniel B; Hiscox, Jessica D; Dixon, Blair J; Potgieter, Johan

2016-09-01

Detailed anatomical models can be produced with consumer-level 3D scanning and printing systems. 3D replication techniques are significant advances for anatomical education as they allow practitioners to more easily introduce diverse or numerous specimens into classrooms. Here we present a methodology for producing anatomical models in-house, with the chondrocranium cartilage from a spiny dogfish (Squalus acanthias) and the skeleton of a cane toad (Rhinella marina) as case studies. 3D digital replicas were produced using two consumer-level scanners and specimens were 3D-printed with selective laser sintering. The fidelity of the two case study models was determined with respect to key anatomical features. Larger-scale features of the dogfish chondrocranium and frog skeleton were all well-resolved and distinct in the 3D digital models, and many finer-scale features were also well-resolved, but some more subtle features were absent from the digital models (e.g. endolymphatic foramina in chondrocranium). All characters identified in the digital chondrocranium could be identified in the subsequent 3D print; however, three characters in the 3D-printed frog skeleton could not be clearly delimited (palatines, parasphenoid and pubis). Characters that were absent in the digital models or 3D prints had low-relief in the original scanned specimen and represent a minor loss of fidelity. Our method description and case studies show that minimal equipment and training is needed to produce durable skeletal specimens. These technologies support the tailored production of models for specific classes or research aims. © 2016 Anatomical Society.

Towards anatomic scale agent-based modeling with a massively parallel spatially explicit general-purpose model of enteric tissue (SEGMEnT_HPC).

PubMed

Cockrell, Robert Chase; Christley, Scott; Chang, Eugene; An, Gary

2015-01-01

Perhaps the greatest challenge currently facing the biomedical research community is the ability to integrate highly detailed cellular and molecular mechanisms to represent clinical disease states as a pathway to engineer effective therapeutics. This is particularly evident in the representation of organ-level pathophysiology in terms of abnormal tissue structure, which, through histology, remains a mainstay in disease diagnosis and staging. As such, being able to generate anatomic scale simulations is a highly desirable goal. While computational limitations have previously constrained the size and scope of multi-scale computational models, advances in the capacity and availability of high-performance computing (HPC) resources have greatly expanded the ability of computational models of biological systems to achieve anatomic, clinically relevant scale. Diseases of the intestinal tract are exemplary examples of pathophysiological processes that manifest at multiple scales of spatial resolution, with structural abnormalities present at the microscopic, macroscopic and organ-levels. In this paper, we describe a novel, massively parallel computational model of the gut, the Spatially Explicitly General-purpose Model of Enteric Tissue_HPC (SEGMEnT_HPC), which extends an existing model of the gut epithelium, SEGMEnT, in order to create cell-for-cell anatomic scale simulations. We present an example implementation of SEGMEnT_HPC that simulates the pathogenesis of ileal pouchitis, and important clinical entity that affects patients following remedial surgery for ulcerative colitis.

Reanalyzing the "far medial" (transcondylar-transtubercular) approach based on three anatomical vectors: the ventral posterolateral corridor.

PubMed

Chakravarthi, Srikant; Monroy-Sosa, Alejandro; Gonen, Lior; Fukui, Melanie; Rovin, Richard; Kojis, Nathaniel; Lindsay, Mark; Khalili, Sammy; Celix, Juanita; Corsten, Martin; Kassam, Amin B

2018-06-01

Endoscopic endonasal access to the jugular foramen and occipital condyle - the transcondylar-transtubercular approach - is anatomically complex and requires detailed knowledge of the relative position of critical neurovascular structures, in order to avoid inadvertent injury and resultant complications. However, access to this region can be confusing as the orientation and relationships of osseous, vascular, and neural structures are very much different from traditional dorsal approaches. This review aims at providing an organizational construct for a more understandable framework in accessing the transcondylar-transtubercular window. The region can be conceptualized using a three-vector coordinate system: vector 1 represents a dorsal or ventral corridor, vector 2 represents the outer and inner circumferential anatomical limits; in an "onion-skin" fashion, key osseous, vascular, and neural landmarks are organized based on a 360-degree skull base model, and vector 3 represents the final core or target of the surgical corridor. The creation of an organized "global-positioning system" may better guide the surgeon in accessing the far-medial transcondylar-transtubercular region, and related pathologies, and help understand the surgical limits to the occipital condyle and jugular foramen - the ventral posterolateral corridor - via the endoscopic endonasal approach.

Use of regularized principal component analysis to model anatomical changes during head and neck radiation therapy for treatment adaptation and response assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chetvertkov, Mikhail A., E-mail: chetvertkov@wayne

2016-10-15

Purpose: To develop standard (SPCA) and regularized (RPCA) principal component analysis models of anatomical changes from daily cone beam CTs (CBCTs) of head and neck (H&N) patients and assess their potential use in adaptive radiation therapy, and for extracting quantitative information for treatment response assessment. Methods: Planning CT images of ten H&N patients were artificially deformed to create “digital phantom” images, which modeled systematic anatomical changes during radiation therapy. Artificial deformations closely mirrored patients’ actual deformations and were interpolated to generate 35 synthetic CBCTs, representing evolving anatomy over 35 fractions. Deformation vector fields (DVFs) were acquired between pCT and syntheticmore » CBCTs (i.e., digital phantoms) and between pCT and clinical CBCTs. Patient-specific SPCA and RPCA models were built from these synthetic and clinical DVF sets. EigenDVFs (EDVFs) having the largest eigenvalues were hypothesized to capture the major anatomical deformations during treatment. Results: Principal component analysis (PCA) models achieve variable results, depending on the size and location of anatomical change. Random changes prevent or degrade PCA’s ability to detect underlying systematic change. RPCA is able to detect smaller systematic changes against the background of random fraction-to-fraction changes and is therefore more successful than SPCA at capturing systematic changes early in treatment. SPCA models were less successful at modeling systematic changes in clinical patient images, which contain a wider range of random motion than synthetic CBCTs, while the regularized approach was able to extract major modes of motion. Conclusions: Leading EDVFs from the both PCA approaches have the potential to capture systematic anatomical change during H&N radiotherapy when systematic changes are large enough with respect to random fraction-to-fraction changes. In all cases the RPCA approach appears to be more reliable at capturing systematic changes, enabling dosimetric consequences to be projected once trends are established early in a treatment course, or based on population models.« less

Utilisation of three-dimensional printed heart models for operative planning of complex congenital heart defects.

PubMed

Olejník, Peter; Nosal, Matej; Havran, Tomas; Furdova, Adriana; Cizmar, Maros; Slabej, Michal; Thurzo, Andrej; Vitovic, Pavol; Klvac, Martin; Acel, Tibor; Masura, Jozef

2017-01-01

To evaluate the accuracy of the three-dimensional (3D) printing of cardiovascular structures. To explore whether utilisation of 3D printed heart replicas can improve surgical and catheter interventional planning in patients with complex congenital heart defects. Between December 2014 and November 2015 we fabricated eight cardiovascular models based on computed tomography data in patients with complex spatial anatomical relationships of cardiovascular structures. A Bland-Altman analysis was used to assess the accuracy of 3D printing by comparing dimension measurements at analogous anatomical locations between the printed models and digital imagery data, as well as between printed models and in vivo surgical findings. The contribution of 3D printed heart models for perioperative planning improvement was evaluated in the four most representative patients. Bland-Altman analysis confirmed the high accuracy of 3D cardiovascular printing. Each printed model offered an improved spatial anatomical orientation of cardiovascular structures. Current 3D printers can produce authentic copies of patients` cardiovascular systems from computed tomography data. The use of 3D printed models can facilitate surgical or catheter interventional procedures in patients with complex congenital heart defects due to better preoperative planning and intraoperative orientation.

["Left hemicranium, the cranial nerves" by Tramond: An anatomical model in wax from the Delmas, Orfila and Rouvière's Museum in Paris: description and tri-dimensional photographic reconstruction (TDPR)].

PubMed

Paravey, S; Le Floch-Prigent, P

2011-06-01

An anatomical model in wax made by Tramond (middle of the 19th century) represented the cranial nerves of a left hemicranium. The aim of the study was to verify its anatomical veracity, to realize a tri-dimensional visualization by computer, and finally to numerize and to diffuse it to the general public in the purpose of culture on the internet. The model belonged to the Delmas, Orfila and Rouvière Museum (Paris Descartes university). It represented the cranial nerves especially the facial and the trigeminal nerves and their branches. To perform the photographic rotation every 5° along 360°, we used a special device made of two identical superimposed marble disks linked by a ball bearing. A digital camera and the Quick Time Virtual Reality software were used. Seventy-two pictures were shot. This wax was realized with a great morphological accuracy from a true cranium as a support for the cranial nerves. The work of numerization and its free diffusion on the Internet permitted to deliver to everybody the images of this sample of the collection of the Orfila Museum, the pieces of which were evacuated on December 2009 after its closure. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Towards Anatomic Scale Agent-Based Modeling with a Massively Parallel Spatially Explicit General-Purpose Model of Enteric Tissue (SEGMEnT_HPC)

PubMed Central

Cockrell, Robert Chase; Christley, Scott; Chang, Eugene; An, Gary

2015-01-01

Perhaps the greatest challenge currently facing the biomedical research community is the ability to integrate highly detailed cellular and molecular mechanisms to represent clinical disease states as a pathway to engineer effective therapeutics. This is particularly evident in the representation of organ-level pathophysiology in terms of abnormal tissue structure, which, through histology, remains a mainstay in disease diagnosis and staging. As such, being able to generate anatomic scale simulations is a highly desirable goal. While computational limitations have previously constrained the size and scope of multi-scale computational models, advances in the capacity and availability of high-performance computing (HPC) resources have greatly expanded the ability of computational models of biological systems to achieve anatomic, clinically relevant scale. Diseases of the intestinal tract are exemplary examples of pathophysiological processes that manifest at multiple scales of spatial resolution, with structural abnormalities present at the microscopic, macroscopic and organ-levels. In this paper, we describe a novel, massively parallel computational model of the gut, the Spatially Explicitly General-purpose Model of Enteric Tissue_HPC (SEGMEnT_HPC), which extends an existing model of the gut epithelium, SEGMEnT, in order to create cell-for-cell anatomic scale simulations. We present an example implementation of SEGMEnT_HPC that simulates the pathogenesis of ileal pouchitis, and important clinical entity that affects patients following remedial surgery for ulcerative colitis. PMID:25806784

Methods and computer executable instructions for rapidly calculating simulated particle transport through geometrically modeled treatment volumes having uniform volume elements for use in radiotherapy

DOEpatents

Frandsen, Michael W.; Wessol, Daniel E.; Wheeler, Floyd J.

2001-01-16

Methods and computer executable instructions are disclosed for ultimately developing a dosimetry plan for a treatment volume targeted for irradiation during cancer therapy. The dosimetry plan is available in "real-time" which especially enhances clinical use for in vivo applications. The real-time is achieved because of the novel geometric model constructed for the planned treatment volume which, in turn, allows for rapid calculations to be performed for simulated movements of particles along particle tracks there through. The particles are exemplary representations of neutrons emanating from a neutron source during BNCT. In a preferred embodiment, a medical image having a plurality of pixels of information representative of a treatment volume is obtained. The pixels are: (i) converted into a plurality of substantially uniform volume elements having substantially the same shape and volume of the pixels; and (ii) arranged into a geometric model of the treatment volume. An anatomical material associated with each uniform volume element is defined and stored. Thereafter, a movement of a particle along a particle track is defined through the geometric model along a primary direction of movement that begins in a starting element of the uniform volume elements and traverses to a next element of the uniform volume elements. The particle movement along the particle track is effectuated in integer based increments along the primary direction of movement until a position of intersection occurs that represents a condition where the anatomical material of the next element is substantially different from the anatomical material of the starting element. This position of intersection is then useful for indicating whether a neutron has been captured, scattered or exited from the geometric model. From this intersection, a distribution of radiation doses can be computed for use in the cancer therapy. The foregoing represents an advance in computational times by multiple factors of time magnitudes.

An imaging-based stochastic model for simulation of tumour vasculature

NASA Astrophysics Data System (ADS)

Adhikarla, Vikram; Jeraj, Robert

2012-10-01

A mathematical model which reconstructs the structure of existing vasculature using patient-specific anatomical, functional and molecular imaging as input was developed. The vessel structure is modelled according to empirical vascular parameters, such as the mean vessel branching angle. The model is calibrated such that the resultant oxygen map modelled from the simulated microvasculature stochastically matches the input oxygen map to a high degree of accuracy (R2 ≈ 1). The calibrated model was successfully applied to preclinical imaging data. Starting from the anatomical vasculature image (obtained from contrast-enhanced computed tomography), a representative map of the complete vasculature was stochastically simulated as determined by the oxygen map (obtained from hypoxia [64Cu]Cu-ATSM positron emission tomography). The simulated microscopic vasculature and the calculated oxygenation map successfully represent the imaged hypoxia distribution (R2 = 0.94). The model elicits the parameters required to simulate vasculature consistent with imaging and provides a key mathematical relationship relating the vessel volume to the tissue oxygen tension. Apart from providing an excellent framework for visualizing the imaging gap between the microscopic and macroscopic imagings, the model has the potential to be extended as a tool to study the dynamics between the tumour and the vasculature in a patient-specific manner and has an application in the simulation of anti-angiogenic therapies.

Pooled genome wide association detects association upstream of FCRL3 with Graves' disease.

PubMed

Khong, Jwu Jin; Burdon, Kathryn P; Lu, Yi; Laurie, Kate; Leonardos, Lefta; Baird, Paul N; Sahebjada, Srujana; Walsh, John P; Gajdatsy, Adam; Ebeling, Peter R; Hamblin, Peter Shane; Wong, Rosemary; Forehan, Simon P; Fourlanos, Spiros; Roberts, Anthony P; Doogue, Matthew; Selva, Dinesh; Montgomery, Grant W; Macgregor, Stuart; Craig, Jamie E

2016-11-18

Graves' disease is an autoimmune thyroid disease of complex inheritance. Multiple genetic susceptibility loci are thought to be involved in Graves' disease and it is therefore likely that these can be identified by genome wide association studies. This study aimed to determine if a genome wide association study, using a pooling methodology, could detect genomic loci associated with Graves' disease. Nineteen of the top ranking single nucleotide polymorphisms including HLA-DQA1 and C6orf10, were clustered within the Major Histo-compatibility Complex region on chromosome 6p21, with rs1613056 reaching genome wide significance (p = 5 × 10 -8 ). Technical validation of top ranking non-Major Histo-compatablity complex single nucleotide polymorphisms with individual genotyping in the discovery cohort revealed four single nucleotide polymorphisms with p ≤ 10 -4 . Rs17676303 on chromosome 1q23.1, located upstream of FCRL3, showed evidence of association with Graves' disease across the discovery, replication and combined cohorts. A second single nucleotide polymorphism rs9644119 downstream of DPYSL2 showed some evidence of association supported by finding in the replication cohort that warrants further study. Pooled genome wide association study identified a genetic variant upstream of FCRL3 as a susceptibility locus for Graves' disease in addition to those identified in the Major Histo-compatibility Complex. A second locus downstream of DPYSL2 is potentially a novel genetic variant in Graves' disease that requires further confirmation.

A novel O-linked glycan modulates Campylobacter jejuni major outer membrane protein-mediated adhesion to human histo-blood group antigens and chicken colonization

PubMed Central

Mahdavi, Jafar; Pirinccioglu, Necmettin; Oldfield, Neil J.; Carlsohn, Elisabet; Stoof, Jeroen; Aslam, Akhmed; Self, Tim; Cawthraw, Shaun A.; Petrovska, Liljana; Colborne, Natalie; Sihlbom, Carina; Borén, Thomas; Wooldridge, Karl G.; Ala'Aldeen, Dlawer A. A.

2014-01-01

Campylobacter jejuni is an important cause of human foodborne gastroenteritis; strategies to prevent infection are hampered by a poor understanding of the complex interactions between host and pathogen. Previous work showed that C. jejuni could bind human histo-blood group antigens (BgAgs) in vitro and that BgAgs could inhibit the binding of C. jejuni to human intestinal mucosa ex vivo. Here, the major flagella subunit protein (FlaA) and the major outer membrane protein (MOMP) were identified as BgAg-binding adhesins in C. jejuni NCTC11168. Significantly, the MOMP was shown to be O-glycosylated at Thr268; previously only flagellin proteins were known to be O-glycosylated in C. jejuni. Substitution of MOMP Thr268 led to significantly reduced binding to BgAgs. The O-glycan moiety was characterized as Gal(β1–3)-GalNAc(β1–4)-GalNAc(β1–4)-GalNAcα1-Thr268; modelling suggested that O-glycosylation has a notable effect on the conformation of MOMP and this modulates BgAg-binding capacity. Glycosylation of MOMP at Thr268 promoted cell-to-cell binding, biofilm formation and adhesion to Caco-2 cells, and was required for the optimal colonization of chickens by C. jejuni, confirming the significance of this O-glycosylation in pathogenesis. PMID:24451549

A COMPARATIVE INVESTIGATION OF THE INFLUENCE OF DERMAL APPENDAGES (HAIR FOLLICLES) ON THE PERCUTANEOUS ABSORPTION OF ORGANOPHOSPHORUS (OP) INSECTICIDES USING QSAR AND PBPK/PD MODELS FOR HUMAN RISK ASSESSMENT

EPA Science Inventory

The successful use of the Exposure Related Dose Estimating Model (ERDEM) for assessment of dermal exposure of humans to OP pesticides requires the input of representative and comparable input parameters. In the specific case of dermal exposure, regional anatomical variation in...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nose, Y.

Methods were developed for generating an integrated, statistical model of the anatomical structures within the human thorax relevant to radioisotope powered artificial heart implantation. These methods involve measurement and analysis of anatomy in four areas: chest wall, pericardium, vascular connections, and great vessels. A model for the prediction of thorax outline from radiograms was finalized. These models were combined with 100 radiograms to arrive at a size distribution representing the adult male and female populations. (CH)

Volumetric Nephrogram Represents Renal Function and Complements Aortic Anatomic Severity Grade in Predicting EVAR Outcomes.

PubMed

Balceniuk, Mark D; Trakimas, Lauren; Aghaie, Claudia; Mix, Doran; Rasheed, Khurram; Seaman, Matthew; Ellis, Jennifer; Glocker, Roan; Doyle, Adam; Stoner, Michael C

2018-07-01

Chronic kidney disease (CKD) is a predictor of poor outcomes for patients undergoing endovascular aortic aneurysm repair (EVAR). Anatomic severity grade (ASG) represents a quantitative mechanism for assessing anatomical suitability for endovascular aortic repair. Anatomic severity grade has been correlated with repair outcomes and resource utilization. The purpose of this study was to identify a novel renal perfusion metric as a way to assist ASG with predicting EVAR outcomes. Retrospective review of a prospectively maintained database identified elective infrarenal aortic aneurysm repair cases. Anatomic grading was undertaken by independent reviewers. Using volumetric software, kidney volume, and a novel measure of kidney functional volume, the volumetric nephrogram (VN) was recorded. Systematic evaluation of the relationship of kidney volume and VN to CKD and ASG was undertaken using linear regression and receiver-operator statistical tools. A total of 386 cases with patient and anatomic data were identified and graded. Mean age was 72.9 ± 0.4 years. Renal volume <281 mL correlated with CKD (area under the curve [AUC] = .708; P ≤ .0001). Volumetric nephrogram <22.5 HU·L correlated with CKD (AUC = 0.764; P ≤ .0001). High (≥15) ASG scores correlated with both renal volume (AUC = .628; P ≤ .0001) and VN (AUC = .628; P ≤ .0001). Regression analysis demonstrated a strong, inverse relationship between ASG and VN ( R 2 = .95). These data demonstrate that VN is a strong predictor of CKD in a large database of patients undergoing elective aneurysm repair. We demonstrate an inverse relationship between renal function and ASG that has not been previously described in the literature. Additionally, we have shown that VN complements ASG as a model of overall cardiovascular health and atherosclerotic burden. Outcomes in patients with poor renal function may be related to anatomical issues in addition to well-described systemic ramifications.

SU-E-J-257: A PCA Model to Predict Adaptive Changes for Head&neck Patients Based On Extraction of Geometric Features From Daily CBCT Datasets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chetvertkov, M; Henry Ford Health System, Detroit, MI; Siddiqui, F

2015-06-15

Purpose: Using daily cone beam CTs (CBCTs) to develop principal component analysis (PCA) models of anatomical changes in head and neck (H&N) patients and to assess the possibility of using these prospectively in adaptive radiation therapy (ART). Methods: Planning CT (pCT) images of 4 H&N patients were deformed to model several different systematic changes in patient anatomy during the course of the radiation therapy (RT). A Pinnacle plugin was used to linearly interpolate the systematic change in patient for the 35 fraction RT course and to generate a set of 35 synthetic CBCTs. Each synthetic CBCT represents the systematic changemore » in patient anatomy for each fraction. Deformation vector fields (DVFs) were acquired between the pCT and synthetic CBCTs with random fraction-to-fraction changes were superimposed on the DVFs. A patient-specific PCA model was built using these DVFs containing systematic plus random changes. It was hypothesized that resulting eigenDVFs (EDVFs) with largest eigenvalues represent the major anatomical deformations during the course of treatment. Results: For all 4 patients, the PCA model provided different results depending on the type and size of systematic change in patient’s body. PCA was more successful in capturing the systematic changes early in the treatment course when these were of a larger scale with respect to the random fraction-to-fraction changes in patient’s anatomy. For smaller scale systematic changes, random changes in patient could completely “hide” the systematic change. Conclusion: The leading EDVF from the patientspecific PCA models could tentatively be identified as a major systematic change during treatment if the systematic change is large enough with respect to random fraction-to-fraction changes. Otherwise, leading EDVF could not represent systematic changes reliably. This work is expected to facilitate development of population-based PCA models that can be used to prospectively identify significant anatomical changes early in treatment. This work is supported in part by a grant from Varian Medical Systems, Palo Alto, CA.« less

Principal component analysis-based anatomical motion models for use in adaptive radiation therapy of head and neck cancer patients

NASA Astrophysics Data System (ADS)

Chetvertkov, Mikhail A.

Purpose: To develop standard and regularized principal component analysis (PCA) models of anatomical changes from daily cone beam CTs (CBCTs) of head and neck (H&N) patients, assess their potential use in adaptive radiation therapy (ART), and to extract quantitative information for treatment response assessment. Methods: Planning CT (pCT) images of H&N patients were artificially deformed to create "digital phantom" images, which modeled systematic anatomical changes during Radiation Therapy (RT). Artificial deformations closely mirrored patients' actual deformations, and were interpolated to generate 35 synthetic CBCTs, representing evolving anatomy over 35 fractions. Deformation vector fields (DVFs) were acquired between pCT and synthetic CBCTs (i.e., digital phantoms), and between pCT and clinical CBCTs. Patient-specific standard PCA (SPCA) and regularized PCA (RPCA) models were built from these synthetic and clinical DVF sets. Eigenvectors, or eigenDVFs (EDVFs), having the largest eigenvalues were hypothesized to capture the major anatomical deformations during treatment. Modeled anatomies were used to assess the dose deviations with respect to the planned dose distribution. Results: PCA models achieve variable results, depending on the size and location of anatomical change. Random changes prevent or degrade SPCA's ability to detect underlying systematic change. RPCA is able to detect smaller systematic changes against the background of random fraction-to-fraction changes, and is therefore more successful than SPCA at capturing systematic changes early in treatment. SPCA models were less successful at modeling systematic changes in clinical patient images, which contain a wider range of random motion than synthetic CBCTs, while the regularized approach was able to extract major modes of motion. For dose assessment it has been shown that the modeled dose distribution was different from the planned dose for the parotid glands due to their shrinkage and shift into the higher dose volumes during the radiotherapy course. Modeled DVHs still underestimated the effect of parotid shrinkage due to the large compression factor (CF) used to acquire DVFs. Conclusion: Leading EDVFs from both PCA approaches have the potential to capture systematic anatomical changes during H&N radiotherapy when systematic changes are large enough with respect to random fraction-to-fraction changes. In all cases the RPCA approach appears to be more reliable than SPCA at capturing systematic changes, enabling dosimetric consequences to be projected to the future treatment fractions based on trends established early in a treatment course, or, potentially, based on population models. This work showed that PCA has a potential in identifying the major mode of anatomical changes during the radiotherapy course and subsequent use of this information in future dose predictions is feasible. Use of smaller CF values for DVFs is preferred, otherwise anatomical motion will be underestimated.

Interactive modeling and simulation of peripheral nerve cords in virtual environments

NASA Astrophysics Data System (ADS)

Ullrich, Sebastian; Frommen, Thorsten; Eckert, Jan; Schütz, Astrid; Liao, Wei; Deserno, Thomas M.; Ntouba, Alexandre; Rossaint, Rolf; Prescher, Andreas; Kuhlen, Torsten

2008-03-01

This paper contributes to modeling, simulation and visualization of peripheral nerve cords. Until now, only sparse datasets of nerve cords can be found. In addition, this data has not yet been used in simulators, because it is only static. To build up a more flexible anatomical structure of peripheral nerve cords, we propose a hierarchical tree data structure where each node represents a nerve branch. The shape of the nerve segments itself is approximated by spline curves. Interactive modeling allows for the creation and editing of control points which are used for branching nerve sections, calculating spline curves and editing spline representations via cross sections. Furthermore, the control points can be attached to different anatomic structures. Through this approach, nerve cords deform in accordance to the movement of the connected structures, e.g., muscles or bones. As a result, we have developed an intuitive modeling system that runs on desktop computers and in immersive environments. It allows anatomical experts to create movable peripheral nerve cords for articulated virtual humanoids. Direct feedback of changes induced by movement or deformation is achieved by visualization in real-time. The techniques and the resulting data are already used for medical simulators.

Histo-blood group antigens as receptors for rotavirus, new understanding on rotavirus epidemiology and vaccine strategy

PubMed Central

Jiang, Xi; Liu, Yang; Tan, Ming

2017-01-01

The success of the two rotavirus (RV) vaccines (Rotarix and RotaTeq) in many countries endorses a live attenuated vaccine approach against RVs. However, the lower efficacies of both vaccines in many low- and middle-income countries indicate a need to improve the current RV vaccines. The recent discovery that RVs recognize histo-blood group antigens (HBGAs) as potential receptors has significantly advanced our understanding of RV diversity, evolution and epidemiology, providing important new insights into the performances of current RV vaccines in different populations and emphasizing a P-type-based vaccine approach. New understanding of RV diversity and evolution also raises a fundamental question about the ‘Jennerian' approach, which needs to be addressed for future development of live attenuated RV vaccines. Alternative approaches to develop safer and more cost-effective subunit vaccines against RVs are also discussed. PMID:28400594

Experiments in concept modeling for radiographic image reports.

PubMed Central

Bell, D S; Pattison-Gordon, E; Greenes, R A

1994-01-01

OBJECTIVE: Development of methods for building concept models to support structured data entry and image retrieval in chest radiography. DESIGN: An organizing model for chest-radiographic reporting was built by analyzing manually a set of natural-language chest-radiograph reports. During model building, clinician-informaticians judged alternative conceptual structures according to four criteria: content of clinically relevant detail, provision for semantic constraints, provision for canonical forms, and simplicity. The organizing model was applied in representing three sample reports in their entirety. To explore the potential for automatic model discovery, the representation of one sample report was compared with the noun phrases derived from the same report by the CLARIT natural-language processing system. RESULTS: The organizing model for chest-radiographic reporting consists of 62 concept types and 17 relations, arranged in an inheritance network. The broadest types in the model include finding, anatomic locus, procedure, attribute, and status. Diagnoses are modeled as a subtype of finding. Representing three sample reports in their entirety added 79 narrower concept types. Some CLARIT noun phrases suggested valid associations among subtypes of finding, status, and anatomic locus. CONCLUSIONS: A manual modeling process utilizing explicitly stated criteria for making modeling decisions produced an organizing model that showed consistency in early testing. A combination of top-down and bottom-up modeling was required. Natural-language processing may inform model building, but algorithms that would replace manual modeling were not discovered. Further progress in modeling will require methods for objective model evaluation and tools for formalizing the model-building process. PMID:7719807

Anatomical modeling of the bronchial tree

NASA Astrophysics Data System (ADS)

Hentschel, Gerrit; Klinder, Tobias; Blaffert, Thomas; Bülow, Thomas; Wiemker, Rafael; Lorenz, Cristian

2010-02-01

The bronchial tree is of direct clinical importance in the context of respective diseases, such as chronic obstructive pulmonary disease (COPD). It furthermore constitutes a reference structure for object localization in the lungs and it finally provides access to lung tissue in, e.g., bronchoscope based procedures for diagnosis and therapy. This paper presents a comprehensive anatomical model for the bronchial tree, including statistics of position, relative and absolute orientation, length, and radius of 34 bronchial segments, going beyond previously published results. The model has been built from 16 manually annotated CT scans, covering several branching variants. The model is represented as a centerline/tree structure but can also be converted in a surface representation. Possible model applications are either to anatomically label extracted bronchial trees or to improve the tree extraction itself by identifying missing segments or sub-trees, e.g., if located beyond a bronchial stenosis. Bronchial tree labeling is achieved using a naïve Bayesian classifier based on the segment properties contained in the model in combination with tree matching. The tree matching step makes use of branching variations covered by the model. An evaluation of the model has been performed in a leaveone- out manner. In total, 87% of the branches resulting from preceding airway tree segmentation could be correctly labeled. The individualized model enables the detection of missing branches, allowing a targeted search, e.g., a local rerun of the tree-segmentation segmentation.

Genes with mutation significance were highly associated with the clinical pattern of patients with breast cancer.

PubMed

Ding, Wan-Jun; Zeng, Tao; Wang, Li-Jun; Lei, Hong-Bo; Ge, Wei; Wang, Zhi

2017-11-17

In the United States, breast cancer is the second leading cause of cancer death in women. Over the past 20 years, breast cancer incidence and mortality rates increased rapidly in developing regions. We aimed to identify the gene mutation patterns that associated with the clinical patterns, including survival status, histo-pathological classes and so forth, of breast cancer. We retrieved 1098 cases of the clinical information, and level-3 legacy data of mRNA expression level, protein expression data and mutation files from GDC data portal. The genes with mutation significance were obtained. We studied the impacts of mutation types on the expression levels of mRNA and protein. Different statistics methods were used to calculate the correlation between the mutation types and the expression data or histo-clinical measures. There were 24 genes with mutation significance identified. The most mutated genes were selected to study the role of specific mutations played on the patients with breast cancer. One interesting finding was the missense mutations on TP53 were related with high expression levels of mRNA and protein. The missense mutations on TP53 were highly related with the morphology, race, ER status, PR status and HER2 Status, while the truncated mutations were only related with the morphology, ER status and PR status. The missense mutation on PIK3CA was highly associated with the morphology, race, ER status and PR status. The mutants with different mutants and the wild type of the most mutated genes had different impacts on the histo-clinical measures that might help personalized therapy.

Adenocarcinoma predominant pattern subtyping and nuclear grading in cytology: Is there a role in prognostication of advanced pulmonary adenocarcinomas?

PubMed

Nambirajan, A; Kaur, H; Jangra, K; Kaur, K; Madan, K; Mathur, S R; Iyer, V K; Jain, D

2018-04-01

Primary lung adenocarcinomas (ADs) show varied architectural patterns, and pattern-based subtyping of ADs is currently recommended due to prognostic implications. Predicting AD patterns on cytology is challenging; however, cytological nuclear features appear to correlate with histological grade and survival in early stage lung ADs. The feasibility and value of AD pattern prediction and nuclear grading on cytology in advanced lung ADs is not known. We aimed to predict patterns and analyse nuclear features on cytology and evaluate their role in prognostication. One-hundred patients of Stage III/IV lung AD with available matched cytology and histology samples were included. Cyto-patterns based on cell arrangement patterns (flat sheets vs three-dimensional clusters vs papillae) and cyto-nuclear score based on nuclear features (size, shape, contour), nucleoli (macronucleoli vs prominent vs inconspicuous), and nuclear chromatin were determined, and correlated with predominant histological-pattern observed on the matched small biopsy and outcome. Higher cyto-nuclear scores were observed with high-grade histo-patterns (solid, micropapillary and cribriform), while the predicted cyto-patterns did not correspond to the predominant pattern on histology in 77% cases. Highest cyto-histo agreement was observed for solid pattern (72%). High grade histo-patterns and cyto-nuclear scores > 3 showed a trend towards inferior survival (not significant). Nuclear grade scoring on cytology is simple to perform, and is predictive of high grade patterns. Its inclusion in routine reporting of cytology samples of lung ADs may be valuable. © 2018 John Wiley & Sons Ltd.

[Non-palpable breast cancer malignant on needle core biopsy and no malignancy in surgical excision: how to manage?].

PubMed

Cheurfa, N; Giard, S

2015-01-01

Despite the standard management of non-palpable breast cancer (needle core biopsy diagnostic, accurate preoperative localization), there are differences in some cases between the malignant histo-pathological finding in diagnostic biopsy results and negative histo-pathological finding after surgical excision. The aim of this study is to evaluate this incidence and classifying them under three category: failure of surgical excision after preoperative identification; removal of the tumor was already completed by percutaneous biopsy; percutaneous biopsy true false positive. We conducted a study based on prospective database, all patients included in this study had partial mastectomy for ductal carcinoma in-situ or invasive cancer which was diagnosed by needle core biopsy and normal/benign after surgery. Regarding the partial mastectomy, 1863 was performed in the last three years in our center. Thirty-seven patients (2%) correspond our study criteria. After discussion of cases in our multidisciplinary reunion, 6 patients (16%) were considered as failure of surgical excision, 26 patients (70%) as true removal of the whole lesion in the core, and 5 patients (13%) as true false-positive cores. This is the first study witch investigate all factors that influence the results of negative final histo-pathological finding of surgical excision of the tumor after malignant diagnostic needle core biopsy. This rare situation need a multidisciplinary meeting to analyse all the steps of management and to determine causes of those false results and try to find adequate management to solve this problem. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Exploring the anatomical encoding of voice with a mathematical model of the vocal system.

PubMed

Assaneo, M Florencia; Sitt, Jacobo; Varoquaux, Gael; Sigman, Mariano; Cohen, Laurent; Trevisan, Marcos A

2016-11-01

The faculty of language depends on the interplay between the production and perception of speech sounds. A relevant open question is whether the dimensions that organize voice perception in the brain are acoustical or depend on properties of the vocal system that produced it. One of the main empirical difficulties in answering this question is to generate sounds that vary along a continuum according to the anatomical properties the vocal apparatus that produced them. Here we use a mathematical model that offers the unique possibility of synthesizing vocal sounds by controlling a small set of anatomically based parameters. In a first stage the quality of the synthetic voice was evaluated. Using specific time traces for sub-glottal pressure and tension of the vocal folds, the synthetic voices generated perceptual responses, which are indistinguishable from those of real speech. The synthesizer was then used to investigate how the auditory cortex responds to the perception of voice depending on the anatomy of the vocal apparatus. Our fMRI results show that sounds are perceived as human vocalizations when produced by a vocal system that follows a simple relationship between the size of the vocal folds and the vocal tract. We found that these anatomical parameters encode the perceptual vocal identity (male, female, child) and show that the brain areas that respond to human speech also encode vocal identity. On the basis of these results, we propose that this low-dimensional model of the vocal system is capable of generating realistic voices and represents a novel tool to explore the voice perception with a precise control of the anatomical variables that generate speech. Furthermore, the model provides an explanation of how auditory cortices encode voices in terms of the anatomical parameters of the vocal system. Copyright © 2016 Elsevier Inc. All rights reserved.

Quantifying lung morphology with respiratory-gated micro-CT in a murine model of emphysema

NASA Astrophysics Data System (ADS)

Ford, N. L.; Martin, E. L.; Lewis, J. F.; Veldhuizen, R. A. W.; Holdsworth, D. W.; Drangova, M.

2009-04-01

Non-invasive micro-CT imaging techniques have been developed to investigate lung structure in free-breathing rodents. In this study, we investigate the utility of retrospectively respiratory-gated micro-CT imaging in an emphysema model to determine if anatomical changes could be observed in the image-derived quantitative analysis at two respiratory phases. The emphysema model chosen was a well-characterized, genetically altered model (TIMP-3 knockout mice) that exhibits a homogeneous phenotype. Micro-CT scans of the free-breathing, anaesthetized mice were obtained in 50 s and retrospectively respiratory sorted and reconstructed, providing 3D images representing peak inspiration and end expiration with 0.15 mm isotropic voxel spacing. Anatomical measurements included the volume and CT density of the lungs and the volume of the major airways, along with the diameters of the trachea, left bronchus and right bronchus. From these measurements, functional parameters such as functional residual capacity and tidal volume were calculated. Significant differences between the wild-type and TIMP-3 knockout groups were observed for measurements of CT density over the entire lung, indicating increased air content in the lungs of TIMP-3 knockout mice. These results demonstrate retrospective respiratory-gated micro-CT, providing images at multiple respiratory phases that can be analyzed quantitatively to investigate anatomical changes in murine models of emphysema.

Fuzzy object modeling

NASA Astrophysics Data System (ADS)

Udupa, Jayaram K.; Odhner, Dewey; Falcao, Alexandre X.; Ciesielski, Krzysztof C.; Miranda, Paulo A. V.; Vaideeswaran, Pavithra; Mishra, Shipra; Grevera, George J.; Saboury, Babak; Torigian, Drew A.

2011-03-01

To make Quantitative Radiology (QR) a reality in routine clinical practice, computerized automatic anatomy recognition (AAR) becomes essential. As part of this larger goal, we present in this paper a novel fuzzy strategy for building bodywide group-wise anatomic models. They have the potential to handle uncertainties and variability in anatomy naturally and to be integrated with the fuzzy connectedness framework for image segmentation. Our approach is to build a family of models, called the Virtual Quantitative Human, representing normal adult subjects at a chosen resolution of the population variables (gender, age). Models are represented hierarchically, the descendents representing organs contained in parent organs. Based on an index of fuzziness of the models, 32 thorax data sets, and 10 organs defined in them, we found that the hierarchical approach to modeling can effectively handle the non-linear relationships in position, scale, and orientation that exist among organs in different patients.

Development of an Interactive Anatomical Three-Dimensional Eye Model

ERIC Educational Resources Information Center

Allen, Lauren K.; Bhattacharyya, Siddhartha; Wilson, Timothy D.

2015-01-01

The discrete anatomy of the eye's intricate oculomotor system is conceptually difficult for novice students to grasp. This is problematic given that this group of muscles represents one of the most common sites of clinical intervention in the treatment of ocular motility disorders and other eye disorders. This project was designed to develop a…

Probabilistic modeling of anatomical variability using a low dimensional parameterization of diffeomorphisms.

PubMed

Zhang, Miaomiao; Wells, William M; Golland, Polina

2017-10-01

We present an efficient probabilistic model of anatomical variability in a linear space of initial velocities of diffeomorphic transformations and demonstrate its benefits in clinical studies of brain anatomy. To overcome the computational challenges of the high dimensional deformation-based descriptors, we develop a latent variable model for principal geodesic analysis (PGA) based on a low dimensional shape descriptor that effectively captures the intrinsic variability in a population. We define a novel shape prior that explicitly represents principal modes as a multivariate complex Gaussian distribution on the initial velocities in a bandlimited space. We demonstrate the performance of our model on a set of 3D brain MRI scans from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. Our model yields a more compact representation of group variation at substantially lower computational cost than the state-of-the-art method such as tangent space PCA (TPCA) and probabilistic principal geodesic analysis (PPGA) that operate in the high dimensional image space. Copyright © 2017 Elsevier B.V. All rights reserved.

Edible Films: Why, What and How!

USDA-ARS?s Scientific Manuscript database

Edible films are becoming more and more important in our life to protect nutritional food from deterioration. Due to strict FDA requirements components of agriculutral products, i.e., cabohydrates, fats and proteins are the most suitable components for this purpose. The chapter describes the histo...

Possible protective effect of royal jelly against cyclophosphamide induced prostatic damage in male albino rats; a biochemical, histological and immuno-histo-chemical study.

PubMed

Abdel-Hafez, Sara Mohammed Naguib; Rifaai, Rehab Ahmed; Abdelzaher, Walaa Yehia

2017-06-01

Almost all the chemotherapy treat many cancer types effectively, but it leads to severe side effects. Chemotherapy like cyclophosphamide (CP) not works only on the active cells, such as cancer cells, but also acts on the healthy cells. Royal jelly (RJ) was reported to have a lot of therapeutic effects besides being an anti-oxidant and anti-cancer agent. The purpose of this study was to assess the possible protective role of RJ in ameliorating the toxic effects of CP overdose in the rat prostatic tissue. The rats were separated into 4 groups; control group, RJ group, CP group and RJ with CP group. Prostatic specimens were processed for biochemical, histological and immune-histo-chemical studies. The mean area fractions of eNOS and Bax expression were measured in all groups, and statistical analysis was carried out. The results showed that in CP treated group, there were marked biological changes in the form of significant increase in prostatic malondialdehyde (MDA) and C - reactive protein (CRP). Additionally there was a significant decrease in glutathione peroxidase (GPx) in prostatic tissue if compared with the control group. Furthermore, the histological changes showed marked acinar and stromal prostatic degeneration. Most prostatic acini showed less PAS reaction and more (eNOS and Bax) expression if compared with the control group. Concomitant administration of RJ with CP revealed a noticeable amelioration of these biochemical and histological changes. In conclusion, RJ provided biochemical and histo-pathological improvement in CP induced prostatic tissue toxicity. These findings revealed that this improvement was associated with a decrease in the tissue oxidative damage and apoptosis. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

A biomechanical comparison of four fixed-angle dorsal plates in a finite element model of dorsally-unstable radius fracture.

PubMed

Knežević, Josip; Kodvanj, Janoš; Čukelj, Fabijan; Pamuković, Frane; Pavić, Arsen

2017-11-01

To compare the finite element models of two different composite radius fracture patterns, reduced and stabilised with four different fixed-angle dorsal plates during axial, dorsal and volar loading conditions. Eight different plastic models representing four AO/ASIF type 23-A3 distal radius fractures and four AO/ASIF 23-C2 distal radius fractures were obtained and fixed each with 1 of 4 methods: a standard dorsal non-anatomical fixed angle T-plate (3.5mm Dorsal T-plate, Synthes), anatomical fixed-angle double plates (2.4mm LCP Dorsal Distal Radius, Synthes), anatomical fixed angle T-plate (2.4mm Acu-Loc Dorsal Plate, Acumed) or anatomical variable-angle dorsal T-plate (3.5mm, Dorsal Plate, Zrinski). Composite radius with plate and screws were scanned with a 3D optical scanner and later processed in Abaqus Software to generate the finite element model. All models were axially loaded at 3 points (centrally, volarly and dorsally) with 50 N forces to avoid the appearance of plastic deformations of the models. Total displacements at the end of the bone and the stresses in the bones and plates were determined and compared. Maximal von Mises stress in bone for 3-part fracture models was very similar to that in 2-part fracture models. The biggest difference between models and the largest displacements were seen during volar loading. The stresses in all models were the highest above the fracture gap. The best performance in all parameters tested was with the Zrinski plate and the most modest results were with the Synthes T-plate. There was no significant difference between 2-part (AO/ASIF type 23-A3) and 3-part (AO/ASIF 23-C2) fracture models. Maximal stresses in the plates appeared above the fracture gap; therefore, it is worth considering the development of plates without screw holes above the gap. © 2017 Elsevier Ltd. All rights reserved.

Glycosaminoglycans and fibrillar collagen in Priapulida: a histo- and cytochemical study.

PubMed

Welsch, U; Erlinger, R; Storch, V

1992-12-01

The distribution of glycosaminoglycans and fibrillar collagen was studied in various tissues of priapulids, which represent an ancient group of marine metazoa. Sulphated glycosaminoglycans, as demonstrated at the electron microscopical level by Cupromeronic blue, were predominantly found in the cuticle, in basement membranes and also in the narrow connective tissue space below epidermis and anterior intestine. On the basis of their morphology the Cupromeronic blue precipitates could be divided into several groups. Fibrillar collagen occurred in the connective tissue under the epidermis and the epithelium of the anterior intestine. The spatial interrelationship between fibrillar collagen and glycosaminoglycans lacked with some exceptions, the high regularity found in connective tissues of other invertebrates and of vertebrates. This might be related to the special skeletal system of priapulids, consisting mainly of a strong extracellular cuticle and the turgor of the fluid-filled body cavity. In such a system the usual supportive structures seem to be of less functional significance.

[On "early pathologic anatomy" and "anatomy of medical structure": continuity or point of epistemological rupture?].

PubMed

Lellouch, Alain

2006-06-01

The aim of this paper is to analyse the technical, conceptual and institutional changes from which, through macroscopic pathology, a new medical science (microscopic pathology) emerged. The "early" pathology was mainly implemented by the Ecole de Paris, at the beginning of the 19th century. After 1850, histo-pathology emerged, in German university institutes (which were separate buildings from the wards and from the dissecting rooms of the hospitals). The birth of histo-pathology is also linked with technical improvements in mass manufactured microscopes, with better techniques for fixing and staining histological samples and lastly, in (1848) withVirchow's cellular theory. Among French doctors, only one, the very famous physician Jean-Martin Charcot (1825-1893) was aware of these dramatic changes. Charcot wrote many texts which are testimonies of an epistemological rupture between two very different types of medicine, the old French "médecine d'hôpital" and the new "lab medicine", developed in German speaking countries and based on the microscope.

Rare Location for Pilonidal Sinus: the Nasal Dorsum.

PubMed

Kars, Ayhan; Atalay, Fatma; Kilic, Korhan; Bingöl, Fatih; Can, Yusuf

2018-05-14

Pilonidal sinuses are recurrent chronic inflammatory lesions which may occur due to penetration of hair particles into skin. Herein, the authors report a pilonidal sinus case that is unusually seen on nasal dorsum and totally excised with the open technique rhinoplasty method. A 20-year-old male patient was admitted to the authors' outpatient clinic with complaints of dysmorphism and discharge from nasal dorsum. Physical examination revealed a swelling in nasal dorsum and hair-containing fistula. Excision was performed with an open rhinoplasty approach. Histo-pathology examination revealed pilonidal sinus. While pilonidal sinus is usually located in sacro-coccygeal region, it may also be seen in atypical localizations like nasal dorsum. Although the prediagnosis of a hair-containing lesion usually includes dermoid cyst, pilonidal sinus should also be considered and histo-pathological examination should certainly be performed. It is a problematic condition when it is symptomatic; however, management and treatment of the disease is easy when correct diagnosis is made.

Immunocytochemical methods to study the distribution of Orientia tsutsugamushi in Leptotrombidium (Acari: Trombiculidae) chiggers.

PubMed

Myint, K S; Linthicum, K J; Tanskul, P; Lerdthusnee, K; Vaughn, D W; Manomuth, C; Mongkolsirichaikul, D; Hansukjariya, P; Hastriter, M W

1998-07-01

Immunocytochemical methods were developed and tested for their ability to detect the distribution of Orientia tsutsugamushi in paraffin sections of adult chiggers (Leptotrombidium imphalum Vercammen-Grandjean & Langston). Rickettsial antigen was detected by application of a simple direct or amplified immunocytochemistry procedure and an indirect immunofluorescent procedure. In the direct procedure alkaline phosphatase conjugation to the mouse polyclonal antibody to the Karp strain was followed by the HistoMark Red test system to detect rickettsial antigen. The amplification procedure used a similar method but used an unlabeled primary antibody followed by secondary biotinylated antimouse IgG, streptavidin-alkaline phosphatase, and the HistoMark Red test system. The immunofluorescent procedure included a biotinylated secondary antibody followed by addition of a streptavidin-FITC conjugate. Specific tissue tropisms in infected chiggers were observed in the salivary glands, nervous tissue, and ovaries of adult female mites in all procedures; however, nonspecific fluorescence of the chigger limited definitive identification of tissue tropisms with the indirect immunofluorescent procedure.

Targeted delivery of brain-derived neurotrophic factor for the treatment of blindness and deafness

PubMed Central

Khalin, Igor; Alyautdin, Renad; Kocherga, Ganna; Bakar, Muhamad Abu

2015-01-01

Neurodegenerative causes of blindness and deafness possess a major challenge in their clinical management as proper treatment guidelines have not yet been found. Brain-derived neurotrophic factor (BDNF) has been established as a promising therapy against neurodegenerative disorders including hearing and visual loss. Unfortunately, the blood–retinal barrier and blood–cochlear barrier, which have a comparable structure to the blood–brain barrier prevent molecules of larger sizes (such as BDNF) from exiting the circulation and reaching the targeted cells. Anatomical features of the eye and ear allow use of local administration, bypassing histo-hematic barriers. This paper focuses on highlighting a variety of strategies proposed for the local administration of the BDNF, like direct delivery, viral gene therapy, and cell-based therapy, which have been shown to successfully improve development, survival, and function of spiral and retinal ganglion cells. The similarities and controversies for BDNF treatment of posterior eye diseases and inner ear diseases have been analyzed and compared. In this review, we also focus on the possibility of translation of this knowledge into clinical practice. And finally, we suggest that using nanoparticulate drug-delivery systems may substantially contribute to the development of clinically viable techniques for BDNF delivery into the cochlea or posterior eye segment, which, ultimately, can lead to a long-term or permanent rescue of auditory and optic neurons from degeneration. PMID:25995632

Liver schwannoma incidentally discovered in a patient with breast cancer.

PubMed

Akin, Murat; Bozkirli, Bahadir; Leventoglu, Sezai; Unal, Kemal; Kapucu, L Ozlem; Akyurek, Nalan; Sare, Mustafa

2009-01-01

Benign schwannomas, also referred to as neurilemomas, neurinomas, and perineural fibroblastomas, are encapsulated nerve sheath tumors. Primary schwannomas of the liver are extremely rare. We present a case of liver schwannoma, incidentally found in a patient with breast cancer. A 66-year-old female consulted her physician for a mass she palpated on her left breast. The abdominal ultrasonography (USG) revealed a 44 x 28 mm mass in the medial segment of the left lobe of her liver suspicious of a metastasis. An USG-guided biopsy was performed and the histo-pathological examination revealed a "peripheral nerve sheath tumor". Positron emission tomography (PET-CT) revealed a pathologic FDG uptake in the lesion that was previously defined in the liver. The tumor resected from the liver was 5 x 4 x 3 cm, yellowish, soft, and capsulated tumor. Microscopic examination revealed that the mass consisted of bundles of spindle cells with hypercellular and hypocellular areas. In immunohistochemistry, there was a strong positive staining for S-100. The tumor was diagnosed as benign liver schwannoma. Schwannomas are benign, encapsulated neoplasms. Symptoms and signs vary depending on the anatomical site and the size of the neoplasm; however, most schwannomas present as an asymptomatic or painless mass. Recurrence is unusual, despite of an incomplete removal, and malignant transformation is exceedingly rare (Fig. 4, Ref. 8). Full Text (Free, PDF) www.bmj.sk.

Nitrite pickling salt as an alternative to formaldehyde for embalming in veterinary anatomy--A study based on histo- and microbiological analyses.

PubMed

Janczyk, Pawel; Weigner, Janet; Luebke-Becker, Antina; Kaessmeyer, Sabine; Plendl, Johanna

2011-02-20

Formaldehyde, the traditional embalming agent has negative health effects. Nitrite pickling salt has been reported to be a good and inexpensive alternative when supplemented with antioxidants, but the antioxidants caused yellowish colouration of cadavers, and damaged corrosion-resistant steel tables and stone floors. Here, nitrite pickling salt was supplemented with ethanol and Pluriol(®) and tested for effectiveness as an embalming agent of twenty dog cadavers: 10 with open, and 10 with closed abdominal cavity. The texture of the tissue was monitored intermittently for 12 months throughout the course of an anatomical dissection class. Histological and microbiological analysis of samples from muscles, lungs, duodenum and colon were performed. Dogs with an open abdomen remained suitable for dissection purposes during the entire course. The abdominal organs of the closed cadavers lost their natural features, without histological signs of autolysis. Enterococcus spp., Staphylococcus spp., Micrococcus spp., Bacillus spp. and Clostridium perfringens were recorded after 24 weeks. The open cadavers underwent additional maintenance via renewed treatment with ethanol and Pluriol(®) after each dissection. After 30 weeks, C. perfringens was massively reduced in the colon of the open cadavers. The tested solution successfully embalms open bodies, carries no health risks and is environmentally friendly and cost effective. Copyright © 2010 Elsevier GmbH. All rights reserved.

Animal models for rotator cuff repair.

PubMed

Lebaschi, Amir; Deng, Xiang-Hua; Zong, Jianchun; Cong, Guang-Ting; Carballo, Camila B; Album, Zoe M; Camp, Christopher; Rodeo, Scott A

2016-11-01

Rotator cuff (RC) injuries represent a significant source of pain, functional impairment, and morbidity. The large disease burden of RC pathologies necessitates rapid development of research methodologies to treat these conditions. Given their ability to model anatomic, biomechanical, cellular, and molecular aspects of the human RC, animal models have played an indispensable role in reducing injury burden and advancing this field of research for many years. The development of animal models in the musculoskeletal (MSK) research arena is uniquely different from that in other fields in that the similarity of macrostructures and functions is as critical to replicate as cellular and molecular functions. Traditionally, larger animals have been used because of their anatomic similarity to humans and the ease of carrying out realistic surgical procedures. However, refinement of current molecular methods, introduction of novel research tools, and advancements in microsurgical techniques have increased the applicability of small animal models in MSK research. In this paper, we review RC animal models and emphasize a murine model that may serve as a valuable instrument for future RC tendon repair investigations. © 2016 New York Academy of Sciences.

Population of anatomically variable 4D XCAT adult phantoms for imaging research and optimization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Segars, W. P.; Bond, Jason; Frush, Jack

2013-04-15

Purpose: The authors previously developed the 4D extended cardiac-torso (XCAT) phantom for multimodality imaging research. The XCAT consisted of highly detailed whole-body models for the standard male and female adult, including the cardiac and respiratory motions. In this work, the authors extend the XCAT beyond these reference anatomies by developing a series of anatomically variable 4D XCAT adult phantoms for imaging research, the first library of 4D computational phantoms. Methods: The initial anatomy of each phantom was based on chest-abdomen-pelvis computed tomography data from normal patients obtained from the Duke University database. The major organs and structures for each phantommore » were segmented from the corresponding data and defined using nonuniform rational B-spline surfaces. To complete the body, the authors manually added on the head, arms, and legs using the original XCAT adult male and female anatomies. The structures were scaled to best match the age and anatomy of the patient. A multichannel large deformation diffeomorphic metric mapping algorithm was then used to calculate the transform from the template XCAT phantom (male or female) to the target patient model. The transform was applied to the template XCAT to fill in any unsegmented structures within the target phantom and to implement the 4D cardiac and respiratory models in the new anatomy. Each new phantom was refined by checking for anatomical accuracy via inspection of the models. Results: Using these methods, the authors created a series of computerized phantoms with thousands of anatomical structures and modeling cardiac and respiratory motions. The database consists of 58 (35 male and 23 female) anatomically variable phantoms in total. Like the original XCAT, these phantoms can be combined with existing simulation packages to simulate realistic imaging data. Each new phantom contains parameterized models for the anatomy and the cardiac and respiratory motions and can, therefore, serve as a jumping point from which to create an unlimited number of 3D and 4D variations for imaging research. Conclusions: A population of phantoms that includes a range of anatomical variations representative of the public at large is needed to more closely mimic a clinical study or trial. The series of anatomically variable phantoms developed in this work provide a valuable resource for investigating 3D and 4D imaging devices and the effects of anatomy and motion in imaging. Combined with Monte Carlo simulation programs, the phantoms also provide a valuable tool to investigate patient-specific dose and image quality, and optimization for adults undergoing imaging procedures.« less

HistoViewer: An Interactive E-learning Platform Facilitating Group and Peer Group Learning

ERIC Educational Resources Information Center

Sander, Bjoern; Golas, Mariola Monika

2013-01-01

Understanding tissue architecture and the morphological characteristics of cells is a central prerequisite to comprehending the basis of physiological tissue function in healthy individuals and relating this to disease states. Traditionally, medical curricula include courses where students examine glass slides of cytological or tissue samples…

Urban land expansion in Quanzhou City, China, 1995-2010

USDA-ARS?s Scientific Manuscript database

With its phenomenal development in recent decades, urbanization in China has been covered in a large number of studies. These studies have focused on large cities, with smaller and lesser known cities largely overlooked. This study analyzed the spatiotemporal changes of land use in Quanzhou, a histo...

Biostereometric Data Processing In ERGODATA: Choice Of Human Body Models

NASA Astrophysics Data System (ADS)

Pineau, J. C.; Mollard, R.; Sauvignon, M.; Amphoux, M.

1983-07-01

The definition of human body models was elaborated with anthropometric data from ERGODATA. The first model reduces the human body into a series of points and lines. The second model is well adapted to represent volumes of each segmentary element. The third is an original model built from the conventional anatomical points. Each segment is defined in space by a tri-angular plane located with its 3-D coordinates. This new model can answer all the processing possibilities in the field of computer-aided design (C.A.D.) in ergonomy but also biomechanics and orthopaedics.

Whole-body and local RF absorption in human models as a function of anatomy and position within 1.5T MR body coil.

PubMed

Murbach, Manuel; Neufeld, Esra; Kainz, Wolfgang; Pruessmann, Klaas P; Kuster, Niels

2014-02-01

Radiofrequency energy deposition in magnetic resonance imaging must be limited to prevent excessive heating of the patient. Correlations of radiofrequency absorption with large-scale anatomical features (e.g., height) are investigated in this article. The specific absorption rate (SAR), as the pivotal parameter for quantifying absorbed radiofrequency, increases with the radial dimension of the patient and therefore with the large-scale anatomical properties. The absorbed energy in six human models has been modeled in different Z-positions (head to knees) within a 1.5T bodycoil. For a fixed B1+ incident field, the whole-body SAR can be up to 2.5 times higher (local SAR up to seven times) in obese adult models compared to children. If the exposure is normalized to 4 W/kg whole-body SAR, the local SAR can well-exceed the limits for local transmit coils and shows intersubject variations of up to a factor of three. The correlations between anatomy and induced local SAR are weak for normalized exposure, but strong for a fixed B1+ field, suggesting that anatomical properties could be used for fast SAR predictions. This study demonstrates that a representative virtual human population is indispensable for the investigation of local SAR levels. Copyright © 2013 Wiley Periodicals, Inc.

Functional Inference of Complex Anatomical Tendinous Networks at a Macroscopic Scale via Sparse Experimentation

PubMed Central

Saxena, Anupam; Lipson, Hod; Valero-Cuevas, Francisco J.

2012-01-01

In systems and computational biology, much effort is devoted to functional identification of systems and networks at the molecular-or cellular scale. However, similarly important networks exist at anatomical scales such as the tendon network of human fingers: the complex array of collagen fibers that transmits and distributes muscle forces to finger joints. This network is critical to the versatility of the human hand, and its function has been debated since at least the 16th century. Here, we experimentally infer the structure (both topology and parameter values) of this network through sparse interrogation with force inputs. A population of models representing this structure co-evolves in simulation with a population of informative future force inputs via the predator-prey estimation-exploration algorithm. Model fitness depends on their ability to explain experimental data, while the fitness of future force inputs depends on causing maximal functional discrepancy among current models. We validate our approach by inferring two known synthetic Latex networks, and one anatomical tendon network harvested from a cadaver's middle finger. We find that functionally similar but structurally diverse models can exist within a narrow range of the training set and cross-validation errors. For the Latex networks, models with low training set error [<4%] and resembling the known network have the smallest cross-validation errors [∼5%]. The low training set [<4%] and cross validation [<7.2%] errors for models for the cadaveric specimen demonstrate what, to our knowledge, is the first experimental inference of the functional structure of complex anatomical networks. This work expands current bioinformatics inference approaches by demonstrating that sparse, yet informative interrogation of biological specimens holds significant computational advantages in accurate and efficient inference over random testing, or assuming model topology and only inferring parameters values. These findings also hold clues to both our evolutionary history and the development of versatile machines. PMID:23144601

Functional inference of complex anatomical tendinous networks at a macroscopic scale via sparse experimentation.

PubMed

Saxena, Anupam; Lipson, Hod; Valero-Cuevas, Francisco J

2012-01-01

In systems and computational biology, much effort is devoted to functional identification of systems and networks at the molecular-or cellular scale. However, similarly important networks exist at anatomical scales such as the tendon network of human fingers: the complex array of collagen fibers that transmits and distributes muscle forces to finger joints. This network is critical to the versatility of the human hand, and its function has been debated since at least the 16(th) century. Here, we experimentally infer the structure (both topology and parameter values) of this network through sparse interrogation with force inputs. A population of models representing this structure co-evolves in simulation with a population of informative future force inputs via the predator-prey estimation-exploration algorithm. Model fitness depends on their ability to explain experimental data, while the fitness of future force inputs depends on causing maximal functional discrepancy among current models. We validate our approach by inferring two known synthetic Latex networks, and one anatomical tendon network harvested from a cadaver's middle finger. We find that functionally similar but structurally diverse models can exist within a narrow range of the training set and cross-validation errors. For the Latex networks, models with low training set error [<4%] and resembling the known network have the smallest cross-validation errors [∼5%]. The low training set [<4%] and cross validation [<7.2%] errors for models for the cadaveric specimen demonstrate what, to our knowledge, is the first experimental inference of the functional structure of complex anatomical networks. This work expands current bioinformatics inference approaches by demonstrating that sparse, yet informative interrogation of biological specimens holds significant computational advantages in accurate and efficient inference over random testing, or assuming model topology and only inferring parameters values. These findings also hold clues to both our evolutionary history and the development of versatile machines.

Computational neuroanatomy: ontology-based representation of neural components and connectivity.

PubMed

Rubin, Daniel L; Talos, Ion-Florin; Halle, Michael; Musen, Mark A; Kikinis, Ron

2009-02-05

A critical challenge in neuroscience is organizing, managing, and accessing the explosion in neuroscientific knowledge, particularly anatomic knowledge. We believe that explicit knowledge-based approaches to make neuroscientific knowledge computationally accessible will be helpful in tackling this challenge and will enable a variety of applications exploiting this knowledge, such as surgical planning. We developed ontology-based models of neuroanatomy to enable symbolic lookup, logical inference and mathematical modeling of neural systems. We built a prototype model of the motor system that integrates descriptive anatomic and qualitative functional neuroanatomical knowledge. In addition to modeling normal neuroanatomy, our approach provides an explicit representation of abnormal neural connectivity in disease states, such as common movement disorders. The ontology-based representation encodes both structural and functional aspects of neuroanatomy. The ontology-based models can be evaluated computationally, enabling development of automated computer reasoning applications. Neuroanatomical knowledge can be represented in machine-accessible format using ontologies. Computational neuroanatomical approaches such as described in this work could become a key tool in translational informatics, leading to decision support applications that inform and guide surgical planning and personalized care for neurological disease in the future.

Can Outer Hair Cells Actively Pump Fluid into the Tunnel of Corti?

NASA Astrophysics Data System (ADS)

Zagadou, Brissi Franck; Mountain, David C.

2011-11-01

Non-classical models of the cochlear traveling wave have been introduced in attempt to capture the unique features of the cochlear amplifier (CA). These models include multiple modes of longitudinal coupling. In one approach, it is hypothesized that two wave modes can add their energies to create amplification such as that desired in the CA. The tunnel of Corti (ToC) was later used to represent the second wave mode for the proposed traveling wave amplifier model, and was incorporated in a multi-compartment cochlea model. The results led to the hypothesis that the CA functions as a fluid pump. However, this hypothesis must be consistent with the anatomical structure of the organ of Corti (OC). The fluid must pass between the outer pillar cells before reaching the ToC, and the ToC fluid and the underlying basilar membrane must constitute an appropriate waveguide. We have analyzed an anatomically based 3D finite element model of the ToC of the gerbil. Our results demonstrate that the OC structure is consistent with the hypothesis.

The challenges in developing a finite element injury model of the neck to predict the penetration of explosively propelled projectiles.

PubMed

Breeze, Johno; Newbery, T; Pope, D; Midwinter, M J

2014-09-01

Neck injuries sustained by UK service personnel serving on current operations from explosively propelled fragments result in significant mortality and long-term morbidity. Many of these injuries could potentially have been prevented had the soldiers been wearing their issued neck collars at the time of injury. The aim of this research is to develop an accurate method of predicting the resultant damage to cervical neurovascular structures from explosively propelled fragments. A finite element numerical model has been developed based on an anatomically accurate, anthropometrically representative 3D mathematical mesh of cervical neurovascular structures. Currently, the model simulates the passage of a fragment simulating projectile through all anatomical components of the neck using material models based upon 20% ballistic gelatin on the simplification that all tissue types act like homogenous muscle. The material models used to define the properties of each element within the model will be sequentially replaced by ones specific to each individual tissue within an anatomical structure. However, the cumulative effect of so many additional variables will necessitate experimental validation against both animal models and post-mortem human subjects to improve the credibility of any predictions made by the model. We believe this approach will in the future have the potential to enable objective comparisons between the mitigative effects of different body armour systems to be made with resultant time and financial savings. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Myelin Associated Inhibitors: A Link Between Injury-Induced and Experience-Dependent Plasticity

PubMed Central

Akbik, Feras; Cafferty, William B. J.; Strittmatter, Stephen M.

2011-01-01

SUMMARY In the adult, both neurologic recovery and anatomical growth after a CNS injury are limited. Two classes of growth inhibitors, myelin associated inhibitors (MAIs) and extracellular matrix associated inhibitors, limit both functional recovery and anatomical rearrangements in animal models of spinal cord injury. Here we focus on how MAIs limit a wide spectrum of growth that includes regeneration, sprouting, and plasticity in both the intact and lesioned CNS. Three classic myelin associated inhibitors, Nogo-A, MAG, and OMgp, signal through their common receptors, Nogo-66 Receptor-1 (NgR1) and Paired-Immunoglobulin-like-Receptor-1 (PirB), to regulate cytoskeletal dynamics and inhibit growth. Initially described as inhibitors of axonal regeneration, subsequent work has demonstrated that MAIs also limit activity and experience-dependent plasticity in the intact, adult CNS. MAIs therefore represent a point of convergence for plasticity that limits anatomical rearrangements regardless of the inciting stimulus, blurring the distinction between injury studies and more “basic” plasticity studies. PMID:21699896

Fluence-to-absorbed-dose conversion coefficients for neutron beams from 0.001 eV to 100 GeV calculated for a set of pregnant female and fetus models

NASA Astrophysics Data System (ADS)

Taranenko, Valery; Xu, X. George

2008-03-01

Protection of fetuses against external neutron exposure is an important task. This paper reports a set of absorbed dose conversion coefficients for fetal and maternal organs for external neutron beams using the RPI-P pregnant female models and the MCNPX code. The newly developed pregnant female models represent an adult female with a fetus including its brain and skeleton at the end of each trimester. The organ masses were adjusted to match the reference values within 1%. For the 3 mm cubic voxel size, the models consist of 10-15 million voxels for 35 organs. External monoenergetic neutron beams of six standard configurations (AP, PA, LLAT, RLAT, ROT and ISO) and source energies 0.001 eV-100 GeV were considered. The results are compared with previous data that are based on simplified anatomical models. The differences in dose depend on source geometry, energy and gestation periods: from 20% up to 140% for the whole fetus, and up to 100% for the fetal brain. Anatomical differences are primarily responsible for the discrepancies in the organ doses. For the first time, the dependence of mother organ doses upon anatomical changes during pregnancy was studied. A maximum of 220% increase in dose was observed for the placenta in the nine months model compared to three months, whereas dose to the pancreas, small and large intestines decreases by 60% for the AP source for the same models. Tabulated dose conversion coefficients for the fetus and 27 maternal organs are provided.

[An anatomical wax of the deep structures of the pelvic limb (by Tramond, 19th century): observation of the tridimensional photographic rotation].

PubMed

Cazenoves, A; Le Floch-Prigent, P

2011-06-01

Anatomical wax modelling was widely used during the 19(th) century, especially in France and Italy. In Paris, The Tramond house was specialized in the realization of this kind of samples. The sample was placed on two large horizontal marble disks, rotating every 5°. We could then describe the sample, verify its anatomical accuracy and also perform a virtual reconstruction with Quick Time Reality QTVR(®) software. The muscular, nervous and arterial elements were represented. We divided the description in three parts: (1) lumbar, pelvic and femoral; (2) femoro-tibial; and (3) tibio-tarsian. We focused the anatomical description on the sciatic nerve; on the organization of the muscles of the gluteal region and the neurovascular organization; and on arterial segmentation. This sample was getting damaged with time, noticeably the representation of the nerves, which are very thin and so, very fragile. Nowadays, 3D representation of the dissected human body is more common, with new techniques such as plastination (Von Hagen's type), which allows one to preserve all the anatomical elements of the subject. This paper and the realization of the virtual museum also aim to participate in a work memory, which recognize the knowledge of the anatomist of wax makers, their teaching quality remained unequalled as their obvious artistical value. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

The effect of anatomical modeling on space radiation dose estimates: a comparison of doses for NASA phantoms and the 5th, 50th, and 95th percentile male and female astronauts.

PubMed

Bahadori, Amir A; Van Baalen, Mary; Shavers, Mark R; Dodge, Charles; Semones, Edward J; Bolch, Wesley E

2011-03-21

The National Aeronautics and Space Administration (NASA) performs organ dosimetry and risk assessment for astronauts using model-normalized measurements of the radiation fields encountered in space. To determine the radiation fields in an organ or tissue of interest, particle transport calculations are performed using self-shielding distributions generated with the computer program CAMERA to represent the human body. CAMERA mathematically traces linear rays (or path lengths) through the computerized anatomical man (CAM) phantom, a computational stylized model developed in the early 1970s with organ and body profiles modeled using solid shapes and scaled to represent the body morphometry of the 1950 50th percentile (PCTL) Air Force male. With the increasing use of voxel phantoms in medical and health physics, a conversion from a mathematical-based to a voxel-based ray-tracing algorithm is warranted. In this study, the voxel-based ray tracer (VoBRaT) is introduced to ray trace voxel phantoms using a modified version of the algorithm first proposed by Siddon (1985 Med. Phys. 12 252-5). After validation, VoBRAT is used to evaluate variations in body self-shielding distributions for NASA phantoms and six University of Florida (UF) hybrid phantoms, scaled to represent the 5th, 50th, and 95th PCTL male and female astronaut body morphometries, which have changed considerably since the inception of CAM. These body self-shielding distributions are used to generate organ dose equivalents and effective doses for five commonly evaluated space radiation environments. It is found that dosimetric differences among the phantoms are greatest for soft radiation spectra and light vehicular shielding.

Automated modification and fusion of voxel models to construct body phantoms with heterogeneous breast tissue: Application to MRI simulations.

PubMed

Rispoli, Joseph V; Wright, Steven M; Malloy, Craig R; McDougall, Mary P

2017-01-01

Human voxel models incorporating detailed anatomical features are vital tools for the computational evaluation of electromagnetic (EM) fields within the body. Besides whole-body human voxel models, phantoms representing smaller heterogeneous anatomical features are often employed; for example, localized breast voxel models incorporating fatty and fibroglandular tissues have been developed for a variety of EM applications including mammography simulation and dosimetry, magnetic resonance imaging (MRI), and ultra-wideband microwave imaging. However, considering wavelength effects, electromagnetic modeling of the breast at sub-microwave frequencies necessitates detailed breast phantoms in conjunction with whole-body voxel models. Heterogeneous breast phantoms are sized to fit within radiofrequency coil hardware, modified by voxel-wise extrusion, and fused to whole-body models using voxel-wise, tissue-dependent logical operators. To illustrate the utility of this method, finite-difference time-domain simulations are performed using a whole-body model integrated with a variety of available breast phantoms spanning the standard four tissue density classifications representing the majority of the population. The software library uses a combination of voxel operations to seamlessly size, modify, and fuse eleven breast phantoms to whole-body voxel models. The software is publicly available on GitHub and is linked to the file exchange at MATLAB ® Central. Simulations confirm the proportions of fatty and fibroglandular tissues in breast phantoms have significant yet predictable implications on projected power deposition in tissue. Breast phantoms may be modified and fused to whole-body voxel models using the software presented in this work; user considerations for the open-source software and resultant phantoms are discussed. Furthermore, results indicate simulating breast models as predominantly fatty tissue can considerably underestimate the potential for tissue heating in women with substantial fibroglandular tissue.

Automated modification and fusion of voxel models to construct body phantoms with heterogeneous breast tissue: Application to MRI simulations

PubMed Central

Rispoli, Joseph V.; Wright, Steven M.; Malloy, Craig R.; McDougall, Mary P.

2017-01-01

Background Human voxel models incorporating detailed anatomical features are vital tools for the computational evaluation of electromagnetic (EM) fields within the body. Besides whole-body human voxel models, phantoms representing smaller heterogeneous anatomical features are often employed; for example, localized breast voxel models incorporating fatty and fibroglandular tissues have been developed for a variety of EM applications including mammography simulation and dosimetry, magnetic resonance imaging (MRI), and ultra-wideband microwave imaging. However, considering wavelength effects, electromagnetic modeling of the breast at sub-microwave frequencies necessitates detailed breast phantoms in conjunction with whole-body voxel models. Methods Heterogeneous breast phantoms are sized to fit within radiofrequency coil hardware, modified by voxel-wise extrusion, and fused to whole-body models using voxel-wise, tissue-dependent logical operators. To illustrate the utility of this method, finite-difference time-domain simulations are performed using a whole-body model integrated with a variety of available breast phantoms spanning the standard four tissue density classifications representing the majority of the population. Results The software library uses a combination of voxel operations to seamlessly size, modify, and fuse eleven breast phantoms to whole-body voxel models. The software is publicly available on GitHub and is linked to the file exchange at MATLAB® Central. Simulations confirm the proportions of fatty and fibroglandular tissues in breast phantoms have significant yet predictable implications on projected power deposition in tissue. Conclusions Breast phantoms may be modified and fused to whole-body voxel models using the software presented in this work; user considerations for the open-source software and resultant phantoms are discussed. Furthermore, results indicate simulating breast models as predominantly fatty tissue can considerably underestimate the potential for tissue heating in women with substantial fibroglandular tissue. PMID:28798837

Rapid purification of fluorescent enzymes by ultrafiltration

NASA Technical Reports Server (NTRS)

Benjaminson, M. A.; Satyanarayana, T.

1983-01-01

In order to expedite the preparation of fluorescently tagged enzymes for histo-cyctochemistry, a previously developed method employing gel column purification was compared with a more rapid modern technique using the Millipore Immersible CX-ultrafilter. Microscopic evaluation of the resulting conjugates showed comparable products. Much time and effort is saved using the new technique.

Rapid purification of fluorescent enzymes by ultrafiltration

NASA Technical Reports Server (NTRS)

Benjaminson, M. A.; Satyanarayana, T.

1983-01-01

In order to expedite the preparation of fluorescently tagged enzymes for histo/cytochemistry, a previously developed method employing gel column purification was compared with a more rapid modern technique using the Millipore Immersible CX-ultrafilter. Microscopic evaluation of the resulting conjugates showed comparable products. Much time and effort is saved using the new technique.

Socio-ecological factors influencing the use of fire to maintain and restore ecosystem health

USDA-ARS?s Scientific Manuscript database

Fire suppression in grassland systems adapted to fire is a major factor that has contributed to recruitment of woody species into grasslands worldwide. Even though the ecology of restoring these fire prone systems back to a grassland state is becoming clearer, the major hurdle to reintroducing histo...

SU-F-R-41: Regularized PCA Can Model Treatment-Related Changes in Head and Neck Patients Using Daily CBCTs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chetvertkov, M; Henry Ford Health System, Detroit, MI; Siddiqui, F

2016-06-15

Purpose: To use daily cone beam CTs (CBCTs) to develop regularized principal component analysis (PCA) models of anatomical changes in head and neck (H&N) patients, to guide replanning decisions in adaptive radiation therapy (ART). Methods: Known deformations were applied to planning CT (pCT) images of 10 H&N patients to model several different systematic anatomical changes. A Pinnacle plugin was used to interpolate systematic changes over 35 fractions, generating a set of 35 synthetic CTs for each patient. Deformation vector fields (DVFs) were acquired between the pCT and synthetic CTs and random fraction-to-fraction changes were superimposed on the DVFs. Standard non-regularizedmore » and regularized patient-specific PCA models were built using the DVFs. The ability of PCA to extract the known deformations was quantified. PCA models were also generated from clinical CBCTs, for which the deformations and DVFs were not known. It was hypothesized that resulting eigenvectors/eigenfunctions with largest eigenvalues represent the major anatomical deformations during the course of treatment. Results: As demonstrated with quantitative results in the supporting document regularized PCA is more successful than standard PCA at capturing systematic changes early in the treatment. Regularized PCA is able to detect smaller systematic changes against the background of random fraction-to-fraction changes. To be successful at guiding ART, regularized PCA should be coupled with models of when anatomical changes occur: early, late or throughout the treatment course. Conclusion: The leading eigenvector/eigenfunction from the both PCA approaches can tentatively be identified as a major systematic change during radiotherapy course when systematic changes are large enough with respect to random fraction-to-fraction changes. In all cases the regularized PCA approach appears to be more reliable at capturing systematic changes, enabling dosimetric consequences to be projected once trends are established early in the treatment course. This work is supported in part by a grant from Varian Medical Systems, Palo Alto, CA.« less

Nasal high flow clears anatomical dead space in upper airway models

PubMed Central

Celik, Gülnaz; Feng, Sheng; Bartenstein, Peter; Meyer, Gabriele; Eickelberg, Oliver; Schmid, Otmar; Tatkov, Stanislav

2015-01-01

Recent studies showed that nasal high flow (NHF) with or without supplemental oxygen can assist ventilation of patients with chronic respiratory and sleep disorders. The hypothesis of this study was to test whether NHF can clear dead space in two different models of the upper nasal airways. The first was a simple tube model consisting of a nozzle to simulate the nasal valve area, connected to a cylindrical tube to simulate the nasal cavity. The second was a more complex anatomically representative upper airway model, constructed from segmented CT-scan images of a healthy volunteer. After filling the models with tracer gases, NHF was delivered at rates of 15, 30, and 45 l/min. The tracer gas clearance was determined using dynamic infrared CO2 spectroscopy and 81mKr-gas radioactive gamma camera imaging. There was a similar tracer-gas clearance characteristic in the tube model and the upper airway model: clearance half-times were below 1.0 s and decreased with increasing NHF rates. For both models, the anterior compartments demonstrated faster clearance levels (half-times < 0.5 s) and the posterior sections showed slower clearance (half-times < 1.0 s). Both imaging methods showed similar flow-dependent tracer-gas clearance in the models. For the anatomically based model, there was complete tracer-gas removal from the nasal cavities within 1.0 s. The level of clearance in the nasal cavities increased by 1.8 ml/s for every 1.0 l/min increase in the rate of NHF. The study has demonstrated the fast-occurring clearance of nasal cavities by NHF therapy, which is capable of reducing of dead space rebreathing. PMID:25882385

Rectal gel application of Withania somnifera root extract expounds anti-inflammatory and muco-restorative activity in TNBS-induced Inflammatory Bowel Disease

PubMed Central

2011-01-01

Background Inflammatory Bowel Disease (IBD) is marked with chronic inflammation of intestinal epithelium driven by oxidative stress. Traditional treatments with plant extracts gained renewed interest due to their ability to ameliorate the multi factorial conditions like inflammation. We investigated the beneficial effects of Withania somnifera in Trinitro Benzyl Sulfonic Acid (TNBS) induced experimental IBD through a rectally applicable formulation. Methods The study included (i) preparation of gel formulation from aqueous Withania somnifera root extract (WSRE), (ii) biochemical assays to determine its performance potential, (iii) testing of formulation efficacy in TNBS-induced IBD rat model, and (iv) histo-patholgical studies to assess its healing and muco-regenerative effect in IBD-induced rats. For this purpose, concentration dependant antioxidant activity of the extracts were evaluated using biochemical assays like (a) inhibition of lipid peroxidation, (b) NO scavenging, (c) H2O2 scavenging, and (d) ferric reducing power assay. Results The extract, at 500 μg/ml, the highest concentration tested, showed 95.6% inhibition of lipid peroxidation, 14.8% NO scavenging, 81.79% H2O2 scavenging and a reducing capacity of 0.80. The results were comparable with standard antioxidants, ascorbic acid and curcumin. WSRE treatment positively scored on histopathological parameters like necrosis, edema, neutrophil infiltration. The post treatment intestinal features showed restoration at par with the healthy intestine. In view of these results, gel formulation containing an aqueous extract of W. somnifera, prepared for rectal application was tested for its anti-inflammatory activity in TNBS-induced rat models for IBD. Commercially available anti-inflammatory drug Mesalamine was used as the standard in this assay. Conclusions Dose of the rectal gel applied at 1000 mg of WSRE per kg rat weight showed significant muco-restorative efficacy in the IBD-induced rats, validated by histo-pathological studies. PMID:21527003

In vitro antioxidant and in vivo hepatoprotective activity of leave extract of Raphanus sativus in rats using CCL4 model.

PubMed

Syed, Shariq Naeem; Rizvi, Waseem; Kumar, Anil; Khan, Aijaz Ahmad; Moin, Shagufta; Ahsan, Akif

2014-01-01

Raphanus sativus is reported to have a variety of biological activities. This work screened the hepato-protective and antioxidant activity of ethanol (ERS), and aqueous (ARS), extracts of leaves of Raphanus sativus in Carbon tetrachloride (CCl4), model in rats. The extracts were subjected to antioxidant tests (Total reducing power and Total phenolic content), and preliminary phytochemical screening. A pilot study was done on 100 and 300 mg/kg extracts, form which 300 mg was chosen for further experiments. The albino rats (200-250 grams), were divided into 5 groups of 6 animals each (n=6). There were three control groups comprising of normal control (normal saline -1ml/kg), negative control group (CCl4 1ml/kg in olive oil in a ratio of 1:1 v/v), and positive control group (Silymarin 50mg/kg). The Test drugs were given in a dose of 300 mg/kg for both ERS and ARS extract for 7 days. Biochemical parameters (AST, ALT, Alkaline phosphatase, Total Bilirubin), histo-pathological examination of liver and in vivo antioxidant tests [CAT, GSH and MDA] were done. The phytochemical study showed the presence of flavanoids, terpenoids, alkaloids, saponins and sterols. A dose dependent increase in the oxidative potential was observed in both the extracts with total phenolic content 70.1 and 44.4 GAE/g extract for ERS and ARS respectively. ERS 300mg/kg showed a significant (p<0.001) increase in levels of AST, ALT and alkaline phosphatase as compared to negative control (percentage hepatoprotection =45.3%) while ARS 300 mg/kg (p<.01) group showed 30% hepatoprotection. The GSH (p<0.001) and CAT (p<0.05) in ERS and ARS were significantly increased while MDA levels were decreased (P< 0.01), as compared negative control. The findings were confirmed histo-pathological examination. The ethanol and aqueous extract of Raphanus sativus have partial hepatoprotection against CCl4 toxicity.

"Mors auxilium vitae"--causes of death of body donors in an Austrian anatomical department.

PubMed

Konschake, Marko; Brenner, Erich

2014-12-01

Anatomical dissection is, despite several critical annotations, a highly valuable component of under- and postgraduate medical education and research. Our current causes-of-death statistics on our body donors is aimed to find out to which extent they are representative of the Austrian population. We evaluated the causes of death stated in their death certificates of a total of 3399 people who donated their bodies to our department in the course of the last 25 years (1988-2013). The categorisation is based on the official ICD-10-WHO classification. Our data show a prevalence of cardiovascular diseases in about half of the donors (42%) examined; no gender difference could be revealed in cardiovascular diseases. Tumours were responsible for about 20% of deaths, lead by lung cancer; cancers showed a slight male excess. All other deaths were caused by diseases of the respiratory system, the digestive organs, the genitourinary system, the nervous system, alimentary and metabolic disorders, infections and blood diseases, psychiatric disorders, external and other causes in descending order. Compared to the official Austrian and German statistics, there are only minor deviations. Our data clearly show that body donors, at least in our department, depict a representative sample of Austrian population in terms of their causes of death. Therefore anatomical dissection provides appropriate insight into the morbidity of the increasing major target population of medicine, the elders. Limitations in the acceptance by age, excluding either young or old donors, which appear to exist in other anatomical departments, will limit this representativeness. Being aware of these facts, the anatomical dissection course cannot only provide anatomical learning experiences but can also provide an introduction to the basics of epidemiology. Therefore, a topographical dissection course remains an indispensable method for both undergraduate and postgraduate training as well as for research.

The importance of spatial ability and mental models in learning anatomy

NASA Astrophysics Data System (ADS)

Chatterjee, Allison K.

As a foundational course in medical education, gross anatomy serves to orient medical and veterinary students to the complex three-dimensional nature of the structures within the body. Understanding such spatial relationships is both fundamental and crucial for achievement in gross anatomy courses, and is essential for success as a practicing professional. Many things contribute to learning spatial relationships; this project focuses on a few key elements: (1) the type of multimedia resources, particularly computer-aided instructional (CAI) resources, medical students used to study and learn; (2) the influence of spatial ability on medical and veterinary students' gross anatomy grades and their mental models; and (3) how medical and veterinary students think about anatomy and describe the features of their mental models to represent what they know about anatomical structures. The use of computer-aided instruction (CAI) by gross anatomy students at Indiana University School of Medicine (IUSM) was assessed through a questionnaire distributed to the regional centers of the IUSM. Students reported using internet browsing, PowerPoint presentation software, and email on a daily bases to study gross anatomy. This study reveals that first-year medical students at the IUSM make limited use of CAI to study gross anatomy. Such studies emphasize the importance of examining students' use of CAI to study gross anatomy prior to development and integration of electronic media into the curriculum and they may be important in future decisions regarding the development of alternative learning resources. In order to determine how students think about anatomical relationships and describe the features of their mental models, personal interviews were conducted with select students based on students' ROT scores. Five typologies of the characteristics of students' mental models were identified and described: spatial thinking, kinesthetic approach, identification of anatomical structures, problem solving strategies, and study methods. Students with different levels of spatial ability visualize and think about anatomy in qualitatively different ways, which is reflected by the features of their mental models. Low spatial ability students thought about and used two-dimensional images from the textbook. They possessed basic two-dimensional models of anatomical structures; they placed emphasis on diagrams and drawings in their studies; and they re-read anatomical problems many times before answering. High spatial ability students thought fully in three-dimensional and imagined rotation and movement of the structures; they made use of many types of images and text as they studied and solved problems. They possessed elaborate three-dimensional models of anatomical structures which they were able to manipulate to solve problems; and they integrated diagrams, drawings, and written text in their studies. Middle spatial ability students were a mix between both low and high spatial ability students. They imagined two-dimensional images popping out of the flat paper to become more three-dimensional, but still relied on drawings and diagrams. Additionally, high spatial ability students used a higher proportion of anatomical terminology than low spatial ability or middle spatial ability students. This provides additional support to the premise that high spatial students' mental models are a complex mixture of imagistic representations and propositional representations that incorporate correct anatomical terminology. Low spatial ability students focused on the function of structures and ways to group information primarily for the purpose of recall. This supports the theory that low spatial students' mental models will be characterized by more on imagistic representations that are general in nature. (Abstract shortened by UMI.)

Cluster-based upper body marker models for three-dimensional kinematic analysis: Comparison with an anatomical model and reliability analysis.

PubMed

Boser, Quinn A; Valevicius, Aïda M; Lavoie, Ewen B; Chapman, Craig S; Pilarski, Patrick M; Hebert, Jacqueline S; Vette, Albert H

2018-04-27

Quantifying angular joint kinematics of the upper body is a useful method for assessing upper limb function. Joint angles are commonly obtained via motion capture, tracking markers placed on anatomical landmarks. This method is associated with limitations including administrative burden, soft tissue artifacts, and intra- and inter-tester variability. An alternative method involves the tracking of rigid marker clusters affixed to body segments, calibrated relative to anatomical landmarks or known joint angles. The accuracy and reliability of applying this cluster method to the upper body has, however, not been comprehensively explored. Our objective was to compare three different upper body cluster models with an anatomical model, with respect to joint angles and reliability. Non-disabled participants performed two standardized functional upper limb tasks with anatomical and cluster markers applied concurrently. Joint angle curves obtained via the marker clusters with three different calibration methods were compared to those from an anatomical model, and between-session reliability was assessed for all models. The cluster models produced joint angle curves which were comparable to and highly correlated with those from the anatomical model, but exhibited notable offsets and differences in sensitivity for some degrees of freedom. Between-session reliability was comparable between all models, and good for most degrees of freedom. Overall, the cluster models produced reliable joint angles that, however, cannot be used interchangeably with anatomical model outputs to calculate kinematic metrics. Cluster models appear to be an adequate, and possibly advantageous alternative to anatomical models when the objective is to assess trends in movement behavior. Copyright © 2018 Elsevier Ltd. All rights reserved.

Anatomy and histology of the newly discovered adipose sac structure within the labia majora: international original research.

PubMed

Ostrzenski, Adam; Krajewski, Pawel; Davis, Kern

2016-09-01

To determine whether there is any new anatomical structure present within the labia majora. A case serial study was executed on eleven consecutive fresh human female cadavers. Stratum-by-stratum dissections of the labia majora were performed. Twenty-two anatomic dissections of labia majora were completed. Eosin and Hematoxylin agents were used to stain newly discovered adipose sac's tissues of the labia majora and the cylinder-like structures, which cover condensed adipose tissues. The histology of these two structures was compared. All dissected labia majora demonstrated the presence of the anatomic existence of the adipose sac structure. Just under the dermis of the labia majora, the adipose sac was located, which was filled with lobules containing condensed fatty tissues in the form of cylinders. The histological investigation established that the well-organized fibro-connective-adipose tissues represented the adipose sac. The absence of descriptions of the adipose sac within the labia majora in traditional anatomic and gynecologic textbooks was noted. In this study group, the newly discovered adipose sac is consistently present within the anatomical structure of the labia majora. The well-organized fibro-connective-adipose tissue represents microscopic characteristic features of the adipose sac.

Chronic administration of phenytoin and pleomorphic adenoma: A case report and review of literature.

PubMed

Maharshi, Vikas; Nagar, Pravesh

2017-01-01

Adverse drug effects that are uncommon or appear only on chronic administration of a drug may not be detected in clinical trials. This explains the need of strict post-marketing vigilance on drug use. Phenytoin administration has been shown in the literature to be associated with development of neoplasia (benign/malignant). In our knowledge current work represents the first case of pleomorphic-adenoma of sub-mandibular salivary gland developed following chronic phenytoin use. A 40 year old male having a history of head trauma twenty years back, had been on tablet phenytoin 100 mg thrice daily since then. One year back he noticed a small swelling in left sub-mandibular region and gradually increasing in size. FNAC and CECT revealed the diagnosis of pleomorphic-adenoma of sub-mandibular salivary gland. Other causes were ruled out. Surgical excision was performed successfully and continuing follow-up with no recurrence at the end of 6 months. Histo-pathogical examination of the tissue did not show any malignant changes.

Binding of HBGA-expressing bacteria does not protect Tulane virus from acute heat stress

USDA-ARS?s Scientific Manuscript database

Human noroviruses (HuNoVs) are the major cause of gastroenteritis outbreaks worldwide. Human noroviruses can interact with histo-blood group antigens (HBGAs) on the surface of mammalian cells as well as bacterial cells. HBGAs have been considered as putative receptors or co-receptors for HuNoVs in m...

Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Pacific Southwest). Common Littleneck Clam.

DTIC Science & Technology

1986-04-01

cells in clam (P. tenerrima) in having December and January (Quayle 1943). w , , radiating ribs more prominent than The growth of gametes reaches a...reproductive cycle levels in intertidal mollusks of of Protothaca stamine ’ using histo- California. Veliger 14(4):365-372. logical, wet weight-dry

High copy number of ovine gammaherpesvirus 2 DNA associated with malignant catarrhal fever-like syndrome in a lamb

USDA-ARS?s Scientific Manuscript database

Domestic and wild sheep are the natural reservoirs for ovine gammaherpesvirus 2 (OvHV-2), the causative agent of sheep-associated malignant catarrhal fever (SA-MCF). Virtually all domestic sheep are infected with OvHV-2 and infection is normally subclinical. MCF-like clinical signs and typical histo...

Historical evolution of anatomical terminology from ancient to modern.

PubMed

Sakai, Tatsuo

2007-06-01

The historical development of anatomical terminology from the ancient to the modern can be divided into five stages. The initial stage is represented by the oldest extant anatomical treatises by Galen of Pergamon in the Roman Empire. The anatomical descriptions by Galen utilized only a limited number of anatomical terms, which were essentially colloquial words in the Greek of this period. In the second stage, Vesalius in the early 16th century described the anatomical structures in his Fabrica with the help of detailed magnificent illustrations. He coined substantially no anatomical terms, but devised a system that distinguished anatomical structures with ordinal numbers. The third stage of development in the late 16th century was marked by innovation of a large number of specific anatomical terms especially for the muscles, vessels and nerves. The main figures at this stage were Sylvius in Paris and Bauhin in Basel. In the fourth stage between Bauhin and the international anatomical terminology, many anatomical textbooks were written mainly in Latin in the 17th century, and in modern languages in the 18th and 19th centuries. Anatomical terms for the same structure were differently expressed by different authors. The last stage began at the end of the 19th century, when the first international anatomical terminology in Latin was published as Nomina anatomica. The anatomical terminology was revised repeatedly until the current Terminologia anatomica both in Latin and English.

Digital preservation of anatomical variation: 3D-modeling of embalmed and plastinated cadaveric specimens using uCT and MRI.

PubMed

Moore, Colin W; Wilson, Timothy D; Rice, Charles L

2017-01-01

Anatomy educators have an opportunity to teach anatomical variations as a part of medical and allied health curricula using both cadaveric and three-dimensional (3D) digital models of these specimens. Beyond published cadaveric case reports, anatomical variations identified during routine gross anatomy dissection can be powerful teaching tools and a medium to discuss several anatomical sub-disciplines from embryology to medical imaging. The purpose of this study is to document how cadaveric anatomical variation identified during routine dissection can be scanned using medical imaging techniques to create two-dimensional axial images and interactive 3D models for teaching and learning of anatomical variations. Three cadaveric specimens (2 formalin embalmed, 1 plastinated) depicting anatomical variations and an embryological malformation were scanned using magnetic resonance imaging (MRI) and micro-computed tomography (μCT) for visualization in cross-section and for creation of 3D volumetric models. Results provide educational options to enable visualization and facilitate learning of anatomical variations from cross-sectional scans. Furthermore, the variations can be highlighted, digitized, modeled and manipulated using 3D imaging software and viewed in the anatomy laboratory in conjunction with traditional anatomical dissection. This study provides an example for anatomy educators to teach and describe anatomical variations in the undergraduate medical curriculum. Copyright © 2016 Elsevier GmbH. All rights reserved.

Computer aided three-dimensional reconstruction and modeling of the pelvis, by using plastinated cross sections, as a powerful tool for morphological investigations.

PubMed

Sora, Mircea-Constantin; Jilavu, Radu; Matusz, Petru

2012-10-01

The aim of this study was to describe a method of developing a computerized model of the human female pelvis using plastinated slices. Computerized reconstruction of anatomical structures is becoming very useful for developing anatomical teaching, research modules and animations. Although databases consisting of serial sections derived from frozen cadaver material exist, plastination represents an alternative method for developing anatomical data useful for computerized reconstruction. A slice anatomy study, using plastinated transparent pelvis cross sections, was performed to obtain a 3D reconstruction. One female human pelvis used for this study, first plastinated as a block, then sliced into thin slices and in the end subjected to 3D computerized reconstruction using WinSURF modeling system (SURFdriver Software). To facilitate the understanding of the complex pelvic floor anatomy on sectional images obtained through MR imaging, and to make the representation more vivid, a female pelvis computer-aided 3D model was created. Qualitative observations revealed that the morphological features of the model were consistent with those displayed by typical cadaveric specimens. The quality of the reconstructed images appeared distinct, especially the spatial positions and complicated relationships of contiguous structures of the female pelvis. All reconstructed structures can be displayed in groups or as a whole and interactively rotated in 3D space. The utilization of plastinates for generating tissue sections is useful for 3D computerized modeling. The 3D model of the female pelvis presented in this paper provides a stereoscopic view to study the adjacent relationship and arrangement of respective pelvis sections. A better understanding of the pelvic floor anatomy is relevant to gynaecologists, radiologists, surgeons, urologists, physical therapists and all professionals who take care of women with pelvic floor dysfunction.

Computational neuroanatomy: ontology-based representation of neural components and connectivity

PubMed Central

Rubin, Daniel L; Talos, Ion-Florin; Halle, Michael; Musen, Mark A; Kikinis, Ron

2009-01-01

Background A critical challenge in neuroscience is organizing, managing, and accessing the explosion in neuroscientific knowledge, particularly anatomic knowledge. We believe that explicit knowledge-based approaches to make neuroscientific knowledge computationally accessible will be helpful in tackling this challenge and will enable a variety of applications exploiting this knowledge, such as surgical planning. Results We developed ontology-based models of neuroanatomy to enable symbolic lookup, logical inference and mathematical modeling of neural systems. We built a prototype model of the motor system that integrates descriptive anatomic and qualitative functional neuroanatomical knowledge. In addition to modeling normal neuroanatomy, our approach provides an explicit representation of abnormal neural connectivity in disease states, such as common movement disorders. The ontology-based representation encodes both structural and functional aspects of neuroanatomy. The ontology-based models can be evaluated computationally, enabling development of automated computer reasoning applications. Conclusion Neuroanatomical knowledge can be represented in machine-accessible format using ontologies. Computational neuroanatomical approaches such as described in this work could become a key tool in translational informatics, leading to decision support applications that inform and guide surgical planning and personalized care for neurological disease in the future. PMID:19208191

Shape-based diagnosis of the aortic valve

NASA Astrophysics Data System (ADS)

Ionasec, Razvan Ioan; Tsymbal, Alexey; Vitanovski, Dime; Georgescu, Bogdan; Zhou, S. Kevin; Navab, Nassir; Comaniciu, Dorin

2009-02-01

Disorders of the aortic valve represent a common cardiovascular disease and an important public-health problem worldwide. Pathological valves are currently determined from 2D images through elaborate qualitative evalu- ations and complex measurements, potentially inaccurate and tedious to acquire. This paper presents a novel diagnostic method, which identies diseased valves based on 3D geometrical models constructed from volumetric data. A parametric model, which includes relevant anatomic landmarks as well as the aortic root and lea ets, represents the morphology of the aortic valve. Recently developed robust segmentation methods are applied to estimate the patient specic model parameters from end-diastolic cardiac CT volumes. A discriminative distance function, learned from equivalence constraints in the product space of shape coordinates, determines the corresponding pathology class based on the shape information encoded by the model. Experiments on a heterogeneous set of 63 patients aected by various diseases demonstrated the performance of our method with 94% correctly classied valves.

Atrial Model Development and Prototype Simulations: CRADA Final Report on Tasks 3 and 4

DOE Office of Scientific and Technical Information (OSTI.GOV)

O'Hara, T.; Zhang, X.; Villongco, C.

2016-10-28

The goal of this CRADA was to develop essential tools needed to simulate human atrial electrophysiology in 3-dimensions using an anatomical image-based anatomy and physiologically detailed human cellular model. The atria were modeled as anisotropic, representing the preferentially longitudinal electrical coupling between myocytes. Across the entire anatomy, cellular electrophysiology was heterogeneous, with left and right atrial myocytes defined differently. Left and right cell types for the “control” case of sinus rhythm (SR) was compared with remodeled electrophysiology and calcium cycling characteristics of chronic atrial fibrillation (cAF). The effects of Isoproterenol (ISO), a beta-adrenergic agonist that represents the functional consequences ofmore » PKA phosphorylation of various ion channels and transporters, was also simulated in SR and cAF to represent atrial activity under physical or emotional stress. Results and findings from Tasks 3 & 4 are described. Tasks 3 and 4 are, respectively: Input parameters prepared for a Cardioid simulation; Report including recommendations for additional scenario development and post-processing analytic strategy.« less

Creation of anatomical models from CT data

NASA Astrophysics Data System (ADS)

Alaytsev, Innokentiy K.; Danilova, Tatyana V.; Manturov, Alexey O.; Mareev, Gleb O.; Mareev, Oleg V.

2018-04-01

Computed tomography is a great source of biomedical data because it allows a detailed exploration of complex anatomical structures. Some structures are not visible on CT scans, and some are hard to distinguish due to partial volume effect. CT datasets require preprocessing before using them as anatomical models in a simulation system. The work describes segmentation and data transformation methods for an anatomical model creation from the CT data. The result models may be used for visual and haptic rendering and drilling simulation in a virtual surgery system.

Central and peripheral reservoirs of feline immunodeficiency virus in cats: a review.

PubMed

Eckstrand, Chrissy D; Sparger, Ellen E; Murphy, Brian G

2017-08-01

Infection with feline immunodeficiency virus (FIV), a lentivirus similar to human immunodeficiency virus (HIV), results in lifelong viral persistence and progressive immunopathology in the cat. FIV has the ability to infect and produce infectious virus in a number of different cell types. FIV provirus can also be maintained in a replication-competent but transcriptionally quiescent state, facilitating viral persistence over time. Immediately after the initial infection, FIV infection quickly disseminates to many anatomical compartments within the host including lymphoid organs, gastrointestinal tract and brain. Collectively, the anatomic and cellular compartments that harbour FIV provirus constitute the viral reservoir and contain foci of both ongoing viral replication and transcriptionally restricted virus that may persist over time. The relative importance of the different phenotypes observed for infected cells, anatomic compartment, replication status and size of the reservoir represent crucial areas of investigation for developing effective viral suppression and eradication therapies. In this review, we discuss what is currently known about FIV reservoirs, and emphasize the utility of the FIV-infected cat as a model for the HIV-infected human.

Respiratory flows during early childhood: Computational models to examine therapeutic aerosols in the developing airways

NASA Astrophysics Data System (ADS)

Tenenbaum-Katan, Janna; Hofemeier, Philipp; Sznitman, Josué; Janna Tenenbaum-Katan Team

2015-11-01

Inhalation therapy is the cornerstone of early-childhood respiratory treatments, as well as a rising potential for systemic drug delivery and pulmonary vaccination. As such, indispensable understanding of respiratory flow phenomena, coupled with particle transport at the deep regions of children's lungs is necessary to attain efficient targeting of aerosol therapy. However, fundamental research of pulmonary transport is overwhelmingly focused on adults. In our study, we have developed an anatomically-inspired computational model of representing pulmonary acinar regions at several age points during a child's development. Our numerical simulations examine respiratory flows and particle deposition maps within the acinar model, accounting for varying age dependant anatomical considerations and ventilation patterns. Resulting deposition maps of aerosols alter with age, such findings might suggest that medication protocols of inhalation therapy in young children should be considered to be accordingly amended with the child's development. Additionally to understanding basic scientific concepts of age effects on aerosol deposition, our research can potentially contribute practical guidelines to therapy protocols, and its' necessary modifications with age. We acknowledge the support of the ISF and the Israeli ministry of Science.

Evidence for a distributed hierarchy of action representation in the brain

PubMed Central

Grafton, Scott T.; de C. Hamilton, Antonia F.

2007-01-01

Complex human behavior is organized around temporally distal outcomes. Behavioral studies based on tasks such as normal prehension, multi-step object use and imitation establish the existence of relative hierarchies of motor control. The retrieval errors in apraxia also support the notion of a hierarchical model for representing action in the brain. In this review, three functional brain imaging studies of action observation using the method of repetition suppression are used to identify a putative neural architecture that supports action understanding at the level of kinematics, object centered goals and ultimately, motor outcomes. These results, based on observation, may match a similar functional anatomic hierarchy for action planning and execution. If this is true, then the findings support a functional anatomic model that is distributed across a set of interconnected brain areas that are differentially recruited for different aspects of goal oriented behavior, rather than a homogeneous mirror neuron system for organizing and understanding all behavior. PMID:17706312

Application of an object-oriented programming paradigm in three-dimensional computer modeling of mechanically active gastrointestinal tissues.

PubMed

Rashev, P Z; Mintchev, M P; Bowes, K L

2000-09-01

The aim of this study was to develop a novel three-dimensional (3-D) object-oriented modeling approach incorporating knowledge of the anatomy, electrophysiology, and mechanics of externally stimulated excitable gastrointestinal (GI) tissues and emphasizing the "stimulus-response" principle of extracting the modeling parameters. The modeling method used clusters of class hierarchies representing GI tissues from three perspectives: 1) anatomical; 2) electrophysiological; and 3) mechanical. We elaborated on the first four phases of the object-oriented system development life-cycle: 1) analysis; 2) design; 3) implementation; and 4) testing. Generalized cylinders were used for the implementation of 3-D tissue objects modeling the cecum, the descending colon, and the colonic circular smooth muscle tissue. The model was tested using external neural electrical tissue excitation of the descending colon with virtual implanted electrodes and the stimulating current density distributions over the modeled surfaces were calculated. Finally, the tissue deformations invoked by electrical stimulation were estimated and represented by a mesh-surface visualization technique.

Two-log increase in sensitivity for detection of Norovirus in complex samples using porcine gastric mucin capture and immunomagnetic separation

USDA-ARS?s Scientific Manuscript database

Human histo-blood group antigens (HBGA) have been identified previously as candidate receptors for human norovirus (NOR). Type A, type H1, Lewis HBGAs have been identified major HBGA for NOR binding. We have identified that pig stomach mucin (PGM) contains group A, type H1, and Lewis b type HBGAs...

Minutes of the Speech Understanding Workshop Convened on 13 November 1975 in Washington, D.C.

DTIC Science & Technology

1975-11-13

Paul Butler and the Technology Utilization progrn for their 76 support. To Dr. Orin Cornett of Gallaudet College, I want to express my thanks for his...to Dr. Ronald S. Hershel and "Messrs. Michael A. M\\’onahan, Timothy C. Strand and Larry B. Stotts for advice and criticism. we Cet article discute une

Detecting Bot-Answerable Questions in Ubuntu Chat

DTIC Science & Technology

2013-10-01

another user’s question (see 1http://ubottu.com/ [13:19] <p5yx> is the netbook remix not available anymore? [13:20] <histo> !unr | p5yx [13:20...ubottu> p5yx: Starting with Ubuntu 11.04, the Ubuntu Netbook Edition is no longer being offered as a separate install as Unity is now standard for all

Comparative evaluation between anatomic and non-anatomic lateral ligament reconstruction techniques in the ankle joint: A computational study.

PubMed

Purevsuren, Tserenchimed; Batbaatar, Myagmarbayar; Khuyagbaatar, Batbayar; Kim, Kyungsoo; Kim, Yoon Hyuk

2018-03-12

Biomechanical studies have indicated that the conventional non-anatomic reconstruction techniques for lateral ankle sprain (LAS) tend to restrict subtalar joint motion compared to intact ankle joints. Excessive restriction in subtalar motion may lead to chronic pain, functional difficulties, and development of osteoarthritis. Therefore, various anatomic surgical techniques to reconstruct both the anterior talofibular and calcaneofibular ligaments have been introduced. In this study, ankle joint stability was evaluated using multibody computational ankle joint model to assess two new anatomic reconstruction and three popular non-anatomic reconstruction techniques. An LAS injury, three popular non-anatomic reconstruction models (Watson-Jones, Evans, and Chrisman-Snook), and two common types of anatomic reconstruction models were developed based on the intact ankle model. The stability of ankle in both talocrural and subtalar joint were evaluated under anterior drawer test (150 N anterior force), inversion test (3 Nm inversion moment), internal rotational test (3 Nm internal rotation moment), and the combined loading test (9 Nm inversion and internal moment as well as 1800 N compressive force). Our overall results show that the two anatomic reconstruction techniques were superior to the non-anatomic reconstruction techniques in stabilizing both talocrural and subtalar joints. Restricted subtalar joint motion, which mainly observed in Watson-Jones and Chrisman-Snook techniques, was not shown in the anatomical reconstructions. Evans technique was beneficial for subtalar joint as it does not restrict subtalar motion, though Evans technique was insufficient for restoring talocrural joint inversion. The anatomical reconstruction techniques best recovered ankle stability.

Multiplex, quantitative cellular analysis in large tissue volumes with clearing-enhanced 3D microscopy (Ce3D)

PubMed Central

Li, Weizhe; Germain, Ronald N.

2017-01-01

Organ homeostasis, cellular differentiation, signal relay, and in situ function all depend on the spatial organization of cells in complex tissues. For this reason, comprehensive, high-resolution mapping of cell positioning, phenotypic identity, and functional state in the context of macroscale tissue structure is critical to a deeper understanding of diverse biological processes. Here we report an easy to use method, clearing-enhanced 3D (Ce3D), which generates excellent tissue transparency for most organs, preserves cellular morphology and protein fluorescence, and is robustly compatible with antibody-based immunolabeling. This enhanced signal quality and capacity for extensive probe multiplexing permits quantitative analysis of distinct, highly intermixed cell populations in intact Ce3D-treated tissues via 3D histo-cytometry. We use this technology to demonstrate large-volume, high-resolution microscopy of diverse cell types in lymphoid and nonlymphoid organs, as well as to perform quantitative analysis of the composition and tissue distribution of multiple cell populations in lymphoid tissues. Combined with histo-cytometry, Ce3D provides a comprehensive strategy for volumetric quantitative imaging and analysis that bridges the gap between conventional section imaging and disassociation-based techniques. PMID:28808033

Introducing 3-Dimensional Printing of a Human Anatomic Pathology Specimen: Potential Benefits for Undergraduate and Postgraduate Education and Anatomic Pathology Practice.

PubMed

Mahmoud, Amr; Bennett, Michael

2015-08-01

Three-dimensional (3D) printing, a rapidly advancing technology, is widely applied in fields such as mechanical engineering and architecture. Three-dimensional printing has been introduced recently into medical practice in areas such as reconstructive surgery, as well as in clinical research. Three-dimensionally printed models of anatomic and autopsy pathology specimens can be used for demonstrating pathology entities to undergraduate medical, dental, and biomedical students, as well as for postgraduate training in examination of gross specimens for anatomic pathology residents and pathology assistants, aiding clinicopathological correlation at multidisciplinary team meetings, and guiding reconstructive surgical procedures. To apply 3D printing in anatomic pathology for teaching, training, and clinical correlation purposes. Multicolored 3D printing of human anatomic pathology specimens was achieved using a ZCorp 510 3D printer (3D Systems, Rock Hill, South Carolina) following creation of a 3D model using Autodesk 123D Catch software (Autodesk, Inc, San Francisco, California). Three-dimensionally printed models of anatomic pathology specimens created included pancreatoduodenectomy (Whipple operation) and radical nephrectomy specimens. The models accurately depicted the topographic anatomy of selected specimens and illustrated the anatomic relation of excised lesions to adjacent normal tissues. Three-dimensional printing of human anatomic pathology specimens is achievable. Advances in 3D printing technology may further improve the quality of 3D printable anatomic pathology specimens.

Contextual cueing of tactile search is coded in an anatomical reference frame.

PubMed

Assumpção, Leonardo; Shi, Zhuanghua; Zang, Xuelian; Müller, Hermann J; Geyer, Thomas

2018-04-01

This work investigates the reference frame(s) underlying tactile context memory, a form of statistical learning in a tactile (finger) search task. In this task, if a searched-for target object is repeatedly encountered within a stable spatial arrangement of task-irrelevant distractors, detecting the target becomes more efficient over time (relative to nonrepeated arrangements), as learned target-distractor spatial associations come to guide tactile search, thus cueing attention to the target location. Since tactile search displays can be represented in several reference frames, including multiple external and an anatomical frame, in Experiment 1 we asked whether repeated search displays are represented in tactile memory with reference to an environment-centered or anatomical reference frame. In Experiment 2, we went on examining a hand-centered versus anatomical reference frame of tactile context memory. Observers performed a tactile search task, divided into a learning and test session. At the transition between the two sessions, we introduced postural manipulations of the hands (crossed ↔ uncrossed in Expt. 1; palm-up ↔ palm-down in Expt. 2) to determine the reference frame of tactile contextual cueing. In both experiments, target-distractor associations acquired during learning transferred to the test session when the placement of the target and distractors was held constant in anatomical, but not external, coordinates. In the latter, RTs were even slower for repeated displays. We conclude that tactile contextual learning is coded in an anatomical reference frame. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Generating classes of 3D virtual mandibles for AR-based medical simulation.

PubMed

Hippalgaonkar, Neha R; Sider, Alexa D; Hamza-Lup, Felix G; Santhanam, Anand P; Jaganathan, Bala; Imielinska, Celina; Rolland, Jannick P

2008-01-01

Simulation and modeling represent promising tools for several application domains from engineering to forensic science and medicine. Advances in 3D imaging technology convey paradigms such as augmented reality (AR) and mixed reality inside promising simulation tools for the training industry. Motivated by the requirement for superimposing anatomically correct 3D models on a human patient simulator (HPS) and visualizing them in an AR environment, the purpose of this research effort was to develop and validate a method for scaling a source human mandible to a target human mandible within a 2 mm root mean square (RMS) error. Results show that, given a distance between 2 same landmarks on 2 different mandibles, a relative scaling factor may be computed. Using this scaling factor, results show that a 3D virtual mandible model can be made morphometrically equivalent to a real target-specific mandible within a 1.30 mm RMS error. The virtual mandible may be further used as a reference target for registering other anatomic models, such as the lungs, on the HPS. Such registration will be made possible by physical constraints among the mandible and the spinal column in the horizontal normal rest position.

Anatomical correlates to the bands seen in the outer retina by optical coherence tomography: literature review and model.

PubMed

Spaide, Richard F; Curcio, Christine A

2011-09-01

To evaluate the validity of commonly used anatomical designations for the four hyperreflective outer retinal bands seen in current-generation optical coherence tomography, a scale model of outer retinal morphology was created using published information for direct comparison with optical coherence tomography scans. Articles and books concerning histology of the outer retina from 1900 until 2009 were evaluated, and data were used to create a scale model drawing. Boundaries between outer retinal tissue compartments described by the model were compared with intensity variations of representative spectral-domain optical coherence tomography scans using longitudinal reflectance profiles to determine the region of origin of the hyperreflective outer retinal bands. This analysis showed a high likelihood that the spectral-domain optical coherence tomography bands attributed to the external limiting membrane (the first, innermost band) and to the retinal pigment epithelium (the fourth, outermost band) are correctly attributed. Comparative analysis showed that the second band, often attributed to the boundary between inner and outer segments of the photoreceptors, actually aligns with the ellipsoid portion of the inner segments. The third band corresponded to an ensheathment of the cone outer segments by apical processes of the retinal pigment epithelium in a structure known as the contact cylinder. Anatomical attributions and subsequent pathophysiologic assessments pertaining to the second and third outer retinal hyperreflective bands may not be correct. This analysis has identified testable hypotheses for the actual correlates of the second and third bands. Nonretinal pigment epithelium contributions to the fourth band (e.g., Bruch membrane) remain to be determined.

Using web-based animations to teach histology.

PubMed

Brisbourne, Marc A S; Chin, Susan S-L; Melnyk, Erica; Begg, David A

2002-02-15

We have been experimenting with the use of animations to teach histology as part of an interactive multimedia program we are developing to replace the traditional lecture/laboratory-based histology course in our medical and dental curricula. This program, called HistoQuest, uses animations to illustrate basic histologic principles, explain dynamic processes, integrate histologic structure with physiological function, and assist students in forming mental models with which to organize and integrate new information into their learning. With this article, we first briefly discuss the theory of mental modeling, principles of visual presentation, and how mental modeling and visual presentation can be integrated to create effective animations. We then discuss the major Web-based animation technologies that are currently available and their suitability for different visual styles and navigational structures. Finally, we describe the process we use to produce animations for our program. The approach described in this study can be used by other developers to create animations for delivery over the Internet for the teaching of histology.

The Neonatal Ventral Hippocampal Lesion (NVHL) Rodent Model of Schizophrenia

PubMed Central

Brady, Anne Marie

2016-01-01

Animal models are crucial to the study of the neurobiological bases of psychiatric disorders, but schizophrenia is a particularly challenging disorder to model given the complexity and heavily verbal nature of its symptoms. This article describes a developmental surgical rodent model of schizophrenia, the neonatal ventral hippocampal lesion (NVHL) model. This widely used model produces reliable behavioral abnormalities that are comparable to those observed in patients, as well as anatomical and neurophysiological disruptions in forebrain areas that are also implicated in schizophrenia. A brief background of the development and validity of the NVHL model is discussed here, along with detailed procedures for producing the model in rats. Critical issues particular to neonatal surgery are discussed, and representative histological and behavioral results are presented. PMID:27696361

An Accurate and Dynamic Computer Graphics Muscle Model

NASA Technical Reports Server (NTRS)

Levine, David Asher

1997-01-01

A computer based musculo-skeletal model was developed at the University in the departments of Mechanical and Biomedical Engineering. This model accurately represents human shoulder kinematics. The result of this model is the graphical display of bones moving through an appropriate range of motion based on inputs of EMGs and external forces. The need existed to incorporate a geometric muscle model in the larger musculo-skeletal model. Previous muscle models did not accurately represent muscle geometries, nor did they account for the kinematics of tendons. This thesis covers the creation of a new muscle model for use in the above musculo-skeletal model. This muscle model was based on anatomical data from the Visible Human Project (VHP) cadaver study. Two-dimensional digital images from the VHP were analyzed and reconstructed to recreate the three-dimensional muscle geometries. The recreated geometries were smoothed, reduced, and sliced to form data files defining the surfaces of each muscle. The muscle modeling function opened these files during run-time and recreated the muscle surface. The modeling function applied constant volume limitations to the muscle and constant geometry limitations to the tendons.

Unusual pattern of the first dorsal metacarpal artery.

PubMed

Bianchi, Homero; Saravia, Diego; Ottone, Nicolas Ernesto

2017-07-01

This report describes an unusual pattern of the first dorsal metacarpal artery (FDMA) regarding its course and termination. This FDMA had an abnormal course, passing deep to various anatomical elements related to the index finger, with unusual termination in the radial and ulnar proper palmar digital arteries feeding the second and third fingers, respectively. There is no mention of this anatomical variation in the literature. We report the possible embryological origin of this case and other variations related to the FDMA. This unusual pattern represents a new reason to consider anatomical knowledge important for surgeons whose procedures are in this area and to ensure an accurate diagnosis and safe treatment of pathologies that might engage this anatomical variation.

Visualization of Stereoscopic Anatomic Models of the Paranasal Sinuses and Cervical Vertebrae from the Surgical and Procedural Perspective

ERIC Educational Resources Information Center

Chen, Jian; Smith, Andrew D.; Khan, Majid A.; Sinning, Allan R.; Conway, Marianne L.; Cui, Dongmei

2017-01-01

Recent improvements in three-dimensional (3D) virtual modeling software allows anatomists to generate high-resolution, visually appealing, colored, anatomical 3D models from computed tomography (CT) images. In this study, high-resolution CT images of a cadaver were used to develop clinically relevant anatomic models including facial skull, nasal…

Machine Vision Within The Framework Of Collective Neural Assemblies

NASA Astrophysics Data System (ADS)

Gupta, Madan M.; Knopf, George K.

1990-03-01

The proposed mechanism for designing a robust machine vision system is based on the dynamic activity generated by the various neural populations embedded in nervous tissue. It is postulated that a hierarchy of anatomically distinct tissue regions are involved in visual sensory information processing. Each region may be represented as a planar sheet of densely interconnected neural circuits. Spatially localized aggregates of these circuits represent collective neural assemblies. Four dynamically coupled neural populations are assumed to exist within each assembly. In this paper we present a state-variable model for a tissue sheet derived from empirical studies of population dynamics. Each population is modelled as a nonlinear second-order system. It is possible to emulate certain observed physiological and psychophysiological phenomena of biological vision by properly programming the interconnective gains . Important early visual phenomena such as temporal and spatial noise insensitivity, contrast sensitivity and edge enhancement will be discussed for a one-dimensional tissue model.

Computational design and engineering of polymeric orthodontic aligners.

PubMed

Barone, S; Paoli, A; Razionale, A V; Savignano, R

2016-10-05

Transparent and removable aligners represent an effective solution to correct various orthodontic malocclusions through minimally invasive procedures. An aligner-based treatment requires patients to sequentially wear dentition-mating shells obtained by thermoforming polymeric disks on reference dental models. An aligner is shaped introducing a geometrical mismatch with respect to the actual tooth positions to induce a loading system, which moves the target teeth toward the correct positions. The common practice is based on selecting the aligner features (material, thickness, and auxiliary elements) by only considering clinician's subjective assessments. In this article, a computational design and engineering methodology has been developed to reconstruct anatomical tissues, to model parametric aligner shapes, to simulate orthodontic movements, and to enhance the aligner design. The proposed approach integrates computer-aided technologies, from tomographic imaging to optical scanning, from parametric modeling to finite element analyses, within a 3-dimensional digital framework. The anatomical modeling provides anatomies, including teeth (roots and crowns), jaw bones, and periodontal ligaments, which are the references for the down streaming parametric aligner shaping. The biomechanical interactions between anatomical models and aligner geometries are virtually reproduced using a finite element analysis software. The methodology allows numerical simulations of patient-specific conditions and the comparative analyses of different aligner configurations. In this article, the digital framework has been used to study the influence of various auxiliary elements on the loading system delivered to a maxillary and a mandibular central incisor during an orthodontic tipping movement. Numerical simulations have shown a high dependency of the orthodontic tooth movement on the auxiliary element configuration, which should then be accurately selected to maximize the aligner's effectiveness. Copyright © 2016 John Wiley & Sons, Ltd.

Computerized tomography-based anatomic description of the porcine liver.

PubMed

Bekheit, Mohamed; Bucur, Petru O; Wartenberg, Mylene; Vibert, Eric

2017-04-01

The knowledge of the anatomic features is imperative for successful modeling of the different surgical situations. This study aims to describe the anatomic features of the porcine using computerized tomography (CT) scan. Thirty large, white, female pigs were included in this study. The CT image acquisition was performed in four-phase contrast study. Subsequently, analysis of the images was performed using syngo.via software (Siemens) to subtract mainly the hepatic artery and its branches. Analysis of the portal and hepatic veins division pattern was performed using the Myrian XP-Liver 1.14.1 software (Intrasense). The mean total liver volume was 915 ± 159 mL. The largest sector in the liver was the right medial one representing around 28 ± 5.7% of the total liver volume. Next in order is the right lateral sector constituting around 24 ± 5%. Its volume is very close to the volume of the left medial sector, which represents around 22 ± 4.7% of the total liver volume. The caudate lobe represents around 8 ± 2% of the total liver volume.The portal vein did not show distinct right and left divisions rather than consecutive branches that come off the main trunk. The hepatic artery frequently trifurcates into left trunk that gives off the right gastric artery and the artery to the left lateral sector, the middle hepatic artery that supplies both the right and the left medial sectors and the right hepatic artery trunk that divides to give anterior branch to the right lateral lobe, branch to the right medial lobe, and at least a branch to the caudate lobe. Frequently, there is a posterior branch that crosses behind the portal vein to the right lateral lobe. The suprahepatic veins join the inferior vena cava in three distinct openings. There are communications between the suprahepatic veins that drain the adjacent sectors. The vein from the right lateral and the right medial sectors drains into a common trunk. The vein from the left lateral and from the left medial sectors drains into a common trunk. A separate opening is usually encountered draining the right medial sector. The caudate lobe drains separately into inferior vena cava caudal to the other veins. Knowledge of the anatomic features of the porcine liver is crucial to the performance of a successful surgical procedure. We herein describe the CT-depicted anatomic features of the porcine liver. Copyright © 2016 Elsevier Inc. All rights reserved.

[Design of cross-sectional anatomical model focused on drainage pathways of paranasal sinuses].

PubMed

Zha, Y; Lv, W; Gao, Y L; Zhu, Z Z; Gao, Z Q

2018-05-01

Objective: To design and produce cross-sectional anatomical models of paranasal sinuses for the purpose of demonstrating drainage pathways of each nasal sinus for the young doctors. Method: We reconstructed the three-dimensional model of sinuses area based on CT scan data, and divided it into 5 thick cross-sectional anatomy models by 4 coronal plane，which cross middle points of agger nasi cell, ethmoid bulla, posterior ethmoid sinuses and sphenoid sinus respectively. Then a 3D printerwas used to make anatomical cross-sectional anatomical models. Result: Successfully produced a digital 3D printing cross-sectional models of paranasal sinuses. Sinus drainage pathways were observed on the models. Conclusion: The cross-sectional anatomical models made by us can exactly and intuitively demonstrate the ostia of each sinus cell and they can help the young doctors to understand and master the key anatomies and relationships which are important to the endoscopic sinus surgery. Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.

Ultrasonographic identification of the anatomical landmarks that define cervical lymph nodes spaces.

PubMed

Lenghel, Lavinia Manuela; Baciuţ, Grigore; Botar-Jid, Carolina; Vasilescu, Dan; Bojan, Anca; Dudea, Sorin M

2013-03-01

The localization of cervical lymph nodes is extremely important in practice for the positive and differential diagnosis as well as the staging of cervical lymphadenopathies. Ultrasonography represents the first line imaging method in the diagnosis of cervical lymphadenopathies due to its excellent resolution and high diagnosis accuracy. The present paper aims to illustrate the ultrasonographic identification of the anatomical landmarks used for the definition of cervical lymphatic spaces. The application of standardized views allows a delineation of clear anatomical landmarks and an accurate localization of the cervical lymph nodes.

Acoustic backscatter models of fish: Gradual or punctuated evolution

NASA Astrophysics Data System (ADS)

Horne, John K.

2004-05-01

Sound-scattering characteristics of aquatic organisms are routinely investigated using theoretical and numerical models. Development of the inverse approach by van Holliday and colleagues in the 1970s catalyzed the development and validation of backscatter models for fish and zooplankton. As the understanding of biological scattering properties increased, so did the number and computational sophistication of backscatter models. The complexity of data used to represent modeled organisms has also evolved in parallel to model development. Simple geometric shapes representing body components or the whole organism have been replaced by anatomically accurate representations derived from imaging sensors such as computer-aided tomography (CAT) scans. In contrast, Medwin and Clay (1998) recommend that fish and zooplankton should be described by simple theories and models, without acoustically superfluous extensions. Since van Holliday's early work, how has data and computational complexity influenced accuracy and precision of model predictions? How has the understanding of aquatic organism scattering properties increased? Significant steps in the history of model development will be identified and changes in model results will be characterized and compared. [Work supported by ONR and the Alaska Fisheries Science Center.

An innovative design for cardiopulmonary resuscitation manikins based on a human-like thorax and embedded flow sensors.

PubMed

Thielen, Mark; Joshi, Rohan; Delbressine, Frank; Bambang Oetomo, Sidarto; Feijs, Loe

2017-03-01

Cardiopulmonary resuscitation manikins are used for training personnel in performing cardiopulmonary resuscitation. State-of-the-art cardiopulmonary resuscitation manikins are still anatomically and physiologically low-fidelity designs. The aim of this research was to design a manikin that offers high anatomical and physiological fidelity and has a cardiac and respiratory system along with integrated flow sensors to monitor cardiac output and air displacement in response to cardiopulmonary resuscitation. This manikin was designed in accordance with anatomical dimensions using a polyoxymethylene rib cage connected to a vertebral column from an anatomical female model. The respiratory system was composed of silicon-coated memory foam mimicking lungs, a polyvinylchloride bronchus and a latex trachea. The cardiovascular system was composed of two sets of latex tubing representing the pulmonary and aortic arteries which were connected to latex balloons mimicking the ventricles and lumped abdominal volumes, respectively. These balloons were filled with Life/form simulation blood and placed inside polyether foam. The respiratory and cardiovascular systems were equipped with flow sensors to gather data in response to chest compressions. Three non-medical professionals performed chest compressions on this manikin yielding data corresponding to force-displacement while the flow sensors provided feedback. The force-displacement tests on this manikin show a desirable nonlinear behaviour mimicking chest compressions during cardiopulmonary resuscitation in humans. In addition, the flow sensors provide valuable data on the internal effects of cardiopulmonary resuscitation. In conclusion, scientifically designed and anatomically high-fidelity designs of cardiopulmonary resuscitation manikins that embed flow sensors can improve physiological fidelity and provide useful feedback data.

A simple method to recover Norovirus from fresh produce with large sample size by using histo-blood group antigens conjugated magnetic beads re-circulating immunomagnetic separation system

USDA-ARS?s Scientific Manuscript database

Noroviruses (NoV) annually cause millions of cases of gastrointestinal disease in the United States. Although NoV outbreaks are generally associated with raw shellfish, particularly oysters, outbreaks have also been known to occur from other common-source food-borne vehicles such as lettuce, frozen...

Recognition of Histo-Blood Group Antigen-Like Carbohydrates in Lettuce by Human GII.4 Norovirus

PubMed Central

Gao, Xiang; Esseili, Malak A.; Lu, Zhongyan; Saif, Linda J.

2016-01-01

ABSTRACT Human norovirus (HuNoV) genogroup II genotype 4 (GII.4) strains account for about 80% of the gastroenteritis outbreaks in the United States. Contaminated food is a major transmission vehicle for this virus. In humans, pigs, and oysters, histo-blood group antigens (HBGAs) act as attachment factors for HuNoVs. In lettuce, although the virus-like particles (VLPs) of a GII.4 HuNoV were found to bind to cell wall carbohydrates, the exact binding site has not been investigated. Here, we show the presence of HBGA-like carbohydrates in the cell wall of lettuce. The digestion of lettuce leaves with cell wall-degrading enzymes exposed more binding sites and significantly increased the level of binding of GII.4 HuNoV VLPs. Competition assays showed that both the HBGA monoclonal antibody, recognizing the H type, and plant lectins, recognizing α-l-fucose in the H type, effectively inhibited VLP binding to lettuce tissues. Lettuce cell wall components were isolated and their NoV VLP binding characteristics were tested by enzyme-linked immunosorbent assays. The binding was inhibited by pretreatment of the lettuce cell wall materials with α-1,2-fucosidase. Collectively, our results indicate that H-type HBGA-like carbohydrates exist in lettuce tissues and that GII.4 HuNoV VLPs can bind the exposed fucose moiety, possibly in the hemicellulose component of the cell wall. IMPORTANCE Salad crops and fruits are increasingly recognized as vehicles for human norovirus (HuNoV) transmission. A recent study showed that HuNoVs specifically bind to the carbohydrates of the lettuce cell wall. Histo-blood group antigens (HBGAs) are carbohydrates and are known as the attachment factors for HuNoV infection in humans. In this study, we show the presence of HBGA-like carbohydrates in lettuce, to which HuNoVs specifically bind. These results suggest that specifically bound HuNoVs cannot be removed by simple washing, which may allow viral transmission to consumers. Our findings provide new information needed for developing potential inhibitors to block binding and prevent contamination. PMID:26969699

Recognition of Histo-Blood Group Antigen-Like Carbohydrates in Lettuce by Human GII.4 Norovirus.

PubMed

Gao, Xiang; Esseili, Malak A; Lu, Zhongyan; Saif, Linda J; Wang, Qiuhong

2016-05-15

Human norovirus (HuNoV) genogroup II genotype 4 (GII.4) strains account for about 80% of the gastroenteritis outbreaks in the United States. Contaminated food is a major transmission vehicle for this virus. In humans, pigs, and oysters, histo-blood group antigens (HBGAs) act as attachment factors for HuNoVs. In lettuce, although the virus-like particles (VLPs) of a GII.4 HuNoV were found to bind to cell wall carbohydrates, the exact binding site has not been investigated. Here, we show the presence of HBGA-like carbohydrates in the cell wall of lettuce. The digestion of lettuce leaves with cell wall-degrading enzymes exposed more binding sites and significantly increased the level of binding of GII.4 HuNoV VLPs. Competition assays showed that both the HBGA monoclonal antibody, recognizing the H type, and plant lectins, recognizing α-l-fucose in the H type, effectively inhibited VLP binding to lettuce tissues. Lettuce cell wall components were isolated and their NoV VLP binding characteristics were tested by enzyme-linked immunosorbent assays. The binding was inhibited by pretreatment of the lettuce cell wall materials with α-1,2-fucosidase. Collectively, our results indicate that H-type HBGA-like carbohydrates exist in lettuce tissues and that GII.4 HuNoV VLPs can bind the exposed fucose moiety, possibly in the hemicellulose component of the cell wall. Salad crops and fruits are increasingly recognized as vehicles for human norovirus (HuNoV) transmission. A recent study showed that HuNoVs specifically bind to the carbohydrates of the lettuce cell wall. Histo-blood group antigens (HBGAs) are carbohydrates and are known as the attachment factors for HuNoV infection in humans. In this study, we show the presence of HBGA-like carbohydrates in lettuce, to which HuNoVs specifically bind. These results suggest that specifically bound HuNoVs cannot be removed by simple washing, which may allow viral transmission to consumers. Our findings provide new information needed for developing potential inhibitors to block binding and prevent contamination. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Cancer du sein au Cameroun, profil histo-épidémiologique: à propos de 3044 cas

PubMed Central

Engbang, Jean Paul Ndamba; Essome, Henri; Koh, Valère Mve; Simo, Godefroy; Essam, Jean Daniel Sime; Mouelle, Albert Sone; Essame, Jean Louis Oyono

2015-01-01

Décrire les caractéristiques épidémiologiques et histo-pathologiques des tumeurs malignes du sein au Cameroun. Il s'agissait d'une étude rétrospective descriptive portant sur les tumeurs malignes du sein, colligées, dans les registres des différents laboratoires d'Anatomie Pathologique publiques et privés repartis dans cinq régions (centre, littoral, Ouest, Nord-ouest, Sud-ouest), pendant une période de 10 ans (2004-2013). Les paramètres étudiés étaient la fréquence, l’âge, le sexe, la localisation, le type et le grade histologique, et les récepteurs hormonaux. Un total de 3044 cas de cancers du sein a été recensé, soit une fréquence annuelle de 304,4 cas en moyenne. Le sexe féminin était le plus représenté avec 2971 cas (97,60%) et les hommes avec 73 cas (2,40%), soit un sexe ratio (H/F) de 0,02. L’âge moyen des patients était de 46±15,87 ans, avec des extrêmes de 13 et 95 ans. Selon la localisation, le sein gauche était atteint dans 1244 cas (52%) et le sein droit dans 1115 cas (47%). Au plan histologique, on retrouvait essentiellement des carcinomes avec 96,50% des cas, des sarcomes 1,39%, des lymphomes 1,07% et la maladie de Paget du mamelon, 1,03%. Les tumeurs épithéliales étaient infiltrantes dans 2049 cas (84,46%), avec une prédominance du carcinome canalaire infiltrant (1870 cas) et non infiltrantes dans 377 cas (15,54%). Le grade histo-pronostic de SBR avait révélé une prédominance du grade II dans 66% des cas. Les cancers du sein restent une pathologie fréquente au Cameroun et atteignent principalement la population féminine en âge de procréer. Ils sont caractérisés par la prédominance du carcinome canalaire infiltrant. PMID:26523182

Development of a patient-specific anatomical foot model from structured light scan data.

PubMed

Lochner, Samuel J; Huissoon, Jan P; Bedi, Sanjeev S

2014-01-01

The use of anatomically accurate finite element (FE) models of the human foot in research studies has increased rapidly in recent years. Uses for FE foot models include advancing knowledge of orthotic design, shoe design, ankle-foot orthoses, pathomechanics, locomotion, plantar pressure, tissue mechanics, plantar fasciitis, joint stress and surgical interventions. Similar applications but for clinical use on a per-patient basis would also be on the rise if it were not for the high costs associated with developing patient-specific anatomical foot models. High costs arise primarily from the expense and challenges of acquiring anatomical data via magnetic resonance imaging (MRI) or computed tomography (CT) and reconstructing the three-dimensional models. The proposed solution morphs detailed anatomy from skin surface geometry and anatomical landmarks of a generic foot model (developed from CT or MRI) to surface geometry and anatomical landmarks acquired from an inexpensive structured light scan of a foot. The method yields a patient-specific anatomical foot model at a fraction of the cost of standard methods. Average error for bone surfaces was 2.53 mm for the six experiments completed. Highest accuracy occurred in the mid-foot and lowest in the forefoot due to the small, irregular bones of the toes. The method must be validated in the intended application to determine if the resulting errors are acceptable.

Clinical Applications of Stochastic Dynamic Models of the Brain, Part I: A Primer.

PubMed

Roberts, James A; Friston, Karl J; Breakspear, Michael

2017-04-01

Biological phenomena arise through interactions between an organism's intrinsic dynamics and stochastic forces-random fluctuations due to external inputs, thermal energy, or other exogenous influences. Dynamic processes in the brain derive from neurophysiology and anatomical connectivity; stochastic effects arise through sensory fluctuations, brainstem discharges, and random microscopic states such as thermal noise. The dynamic evolution of systems composed of both dynamic and random effects can be studied with stochastic dynamic models (SDMs). This article, Part I of a two-part series, offers a primer of SDMs and their application to large-scale neural systems in health and disease. The companion article, Part II, reviews the application of SDMs to brain disorders. SDMs generate a distribution of dynamic states, which (we argue) represent ideal candidates for modeling how the brain represents states of the world. When augmented with variational methods for model inversion, SDMs represent a powerful means of inferring neuronal dynamics from functional neuroimaging data in health and disease. Together with deeper theoretical considerations, this work suggests that SDMs will play a unique and influential role in computational psychiatry, unifying empirical observations with models of perception and behavior. Copyright © 2017 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Evaluation by medical students of the educational value of multi-material and multi-colored three-dimensional printed models of the upper limb for anatomical education.

PubMed

Mogali, Sreenivasulu Reddy; Yeong, Wai Yee; Tan, Heang Kuan Joel; Tan, Gerald Jit Shen; Abrahams, Peter H; Zary, Nabil; Low-Beer, Naomi; Ferenczi, Michael Alan

2018-01-01

For centuries, cadaveric material has been the cornerstone of anatomical education. For reasons of changes in curriculum emphasis, cost, availability, expertise, and ethical concerns, several medical schools have replaced wet cadaveric specimens with plastinated prosections, plastic models, imaging, and digital models. Discussions about the qualities and limitations of these alternative teaching resources are on-going. We hypothesize that three-dimensional printed (3DP) models can replace or indeed enhance existing resources for anatomical education. A novel multi-colored and multi-material 3DP model of the upper limb was developed based on a plastinated upper limb prosection, capturing muscles, nerves, arteries and bones with a spatial resolution of ∼1 mm. This study aims to examine the educational value of the 3DP model from the learner's point of view. Students (n = 15) compared the developed 3DP models with the plastinated prosections, and provided their views on their learning experience using 3DP models using a survey and focus group discussion. Anatomical features in 3DP models were rated as accurate by all students. Several positive aspects of 3DP models were highlighted, such as the color coding by tissue type, flexibility and that less care was needed in the handling and examination of the specimen than plastinated specimens which facilitated the appreciation of relations between the anatomical structures. However, students reported that anatomical features in 3DP models are less realistic compared to the plastinated specimens. Multi-colored, multi-material 3DP models are a valuable resource for anatomical education and an excellent adjunct to wet cadaveric or plastinated prosections. Anat Sci Educ 11: 54-64. © 2017 American Association of Anatomists. © 2017 American Association of Anatomists.

[3D modeling of the female pelvis by Computer-Assisted Anatomical Dissection: Applications and perspectives].

PubMed

Balaya, V; Uhl, J-F; Lanore, A; Salachas, C; Samoyeau, T; Ngo, C; Bensaid, C; Cornou, C; Rossi, L; Douard, R; Bats, A-S; Lecuru, F; Delmas, V

2016-05-01

To achieve a 3D vectorial model of a female pelvis by Computer-Assisted Anatomical Dissection and to assess educationnal and surgical applications. From the database of "visible female" of Visible Human Project(®) (VHP) of the "national library of medicine" NLM (United States), we used 739 transverse anatomical slices of 0.33mm thickness going from L4 to the trochanters. The manual segmentation of each anatomical structures was done with Winsurf(®) software version 4.3. Each anatomical element was built as a separate vectorial object. The whole colored-rendered vectorial model with realistic textures was exported in 3Dpdf format to allow a real time interactive manipulation with Acrobat(®) pro version 11 software. Each element can be handled separately at any transparency, which allows an anatomical learning by systems: skeleton, pelvic organs, urogenital system, arterial and venous vascularization. This 3D anatomical model can be used as data bank to teach of the fundamental anatomy. This 3D vectorial model, realistic and interactive constitutes an efficient educational tool for the teaching of the anatomy of the pelvis. 3D printing of the pelvis is possible with the new printers. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Textural analysis of optical coherence tomography skin images: quantitative differentiation between healthy and cancerous tissues

NASA Astrophysics Data System (ADS)

Adabi, Saba; Conforto, Silvia; Hosseinzadeh, Matin; Noe, Shahryar; Daveluy, Steven; Mehregan, Darius; Nasiriavanaki, Mohammadreza

2017-02-01

Optical Coherence Tomography (OCT) offers real-time high-resolution three-dimensional images of tissue microstructures. In this study, we used OCT skin images acquired from ten volunteers, neither of whom had any skin conditions addressing the features of their anatomic location. OCT segmented images are analyzed based on their optical properties (attenuation coefficient) and textural image features e.g., contrast, correlation, homogeneity, energy, entropy, etc. Utilizing the information and referring to their clinical insight, we aim to make a comprehensive computational model for the healthy skin. The derived parameters represent the OCT microstructural morphology and might provide biological information for generating an atlas of normal skin from different anatomic sites of human skin and may allow for identification of cell microstructural changes in cancer patients. We then compared the parameters of healthy samples with those of abnormal skin and classified them using a linear Support Vector Machines (SVM) with 82% accuracy.

[Suture simulator - Cleft palate surgery].

PubMed

Devinck, F; Riot, S; Qassemyar, A; Belkhou, A; Wolber, A; Martinot Duquennoy, V; Guerreschi, P

2017-04-01

Cleft palate requires surgery in the first years of life, furthermore repairing anatomically the soft and hard palate is complex on a surgical level because of the fine tissues and the local intraoral configuration. It is valuable to train first on simulators before going to the operating room. However, there is no material dedicated to learning how to perform intraoral sutures in cleft palate surgery. We made one, in an artisanal manner, in order to practice before the real surgical gesture. The simulator was designed based on precise anatomical data. A steel pipe, fixed on a rigid base represented the oral cavity. An adapted split spoon represented the palate. All pieces could be removed in order to apply a hydrocellular dressing before training for sutures. Our simulator was tested by 3 senior surgeons in our department in close to real-life conditions in order to evaluate its anatomical accuracy. It is valuable to have a simulator to train on cleft palate sutures within teaching university hospitals that manage this pathology. Our simulator has a very low cost, it is easy to make and is anatomically accurate. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Atlas warping for brain morphometry

NASA Astrophysics Data System (ADS)

Machado, Alexei M. C.; Gee, James C.

1998-06-01

In this work, we describe an automated approach to morphometry based on spatial normalizations of the data, and demonstrate its application to the analysis of gender differences in the human corpus callosum. The purpose is to describe a population by a reduced and representative set of variables, from which a prior model can be constructed. Our approach is rooted in the assumption that individual anatomies can be considered as quantitative variations on a common underlying qualitative plane. We can therefore imagine that a given individual's anatomy is a warped version of some referential anatomy, also known as an atlas. The spatial warps which transform a labeled atlas into anatomic alignment with a population yield immediate knowledge about organ size and shape in the group. Furthermore, variation within the set of spatial warps is directly related to the anatomic variation among the subjects. Specifically, the shape statistics--mean and variance of the mappings--for the population can be calculated in a special basis, and an eigendecomposition of the variance performed to identify the most significant modes of shape variation. The results obtained with the corpus callosum study confirm the existence of substantial anatomical differences between males and females, as reported in previous experimental work.

Using 3D modeling techniques to enhance teaching of difficult anatomical concepts

PubMed Central

Pujol, Sonia; Baldwin, Michael; Nassiri, Joshua; Kikinis, Ron; Shaffer, Kitt

2016-01-01

Rationale and Objectives Anatomy is an essential component of medical education as it is critical for the accurate diagnosis in organs and human systems. The mental representation of the shape and organization of different anatomical structures is a crucial step in the learning process. The purpose of this pilot study is to demonstrate the feasibility and benefits of developing innovative teaching modules for anatomy education of first-year medical students based on 3D reconstructions from actual patient data. Materials and Methods A total of 196 models of anatomical structures from 16 anonymized CT datasets were generated using the 3D Slicer open-source software platform. The models focused on three anatomical areas: the mediastinum, the upper abdomen and the pelvis. Online optional quizzes were offered to first-year medical students to assess their comprehension in the areas of interest. Specific tasks were designed for students to complete using the 3D models. Results Scores of the quizzes confirmed a lack of understanding of 3D spatial relationships of anatomical structures despite standard instruction including dissection. Written task material and qualitative review by students suggested that interaction with 3D models led to a better understanding of the shape and spatial relationships among structures, and helped illustrate anatomical variations from one body to another. Conclusion The study demonstrates the feasibility of one possible approach to the generation of 3D models of the anatomy from actual patient data. The educational materials developed have the potential to supplement the teaching of complex anatomical regions and help demonstrate the anatomic variation among patients. PMID:26897601

Three-Dimensional Printed Modeling of Diffuse Low-Grade Gliomas and Associated White Matter Tract Anatomy.

PubMed

Thawani, Jayesh P; Singh, Nickpreet; Pisapia, Jared M; Abdullah, Kalil G; Parker, Drew; Pukenas, Bryan A; Zager, Eric L; Verma, Ragini; Brem, Steven

2017-04-01

Diffuse low-grade gliomas (DLGGs) represent several pathological entities that infiltrate and invade cortical and subcortical structures in the brain. To describe methods for rapid prototyping of DLGGs and surgically relevant anatomy. Using high-definition imaging data and rapid prototyping technologies, we were able to generate 3 patient DLGGs to scale and represent the associated white matter tracts in 3 dimensions using advanced diffusion tensor imaging techniques. This report represents a novel application of 3-dimensional (3-D) printing in neurosurgery and a means to model individualized tumors in 3-D space with respect to subcortical white matter tract anatomy. Faculty and resident evaluations of this technology were favorable at our institution. Developing an understanding of the anatomic relationships existing within individuals is fundamental to successful neurosurgical therapy. Imaging-based rapid prototyping may improve on our ability to plan for and treat complex neuro-oncologic pathology. Copyright © 2017 by the Congress of Neurological Surgeons

A statistical parts-based appearance model of inter-subject variability.

PubMed

Toews, Matthew; Collins, D Louis; Arbel, Tal

2006-01-01

In this article, we present a general statistical parts-based model for representing the appearance of an image set, applied to the problem of inter-subject MR brain image matching. In contrast with global image representations such as active appearance models, the parts-based model consists of a collection of localized image parts whose appearance, geometry and occurrence frequency are quantified statistically. The parts-based approach explicitly addresses the case where one-to-one correspondence does not exist between subjects due to anatomical differences, as parts are not expected to occur in all subjects. The model can be learned automatically, discovering structures that appear with statistical regularity in a large set of subject images, and can be robustly fit to new images, all in the presence of significant inter-subject variability. As parts are derived from generic scale-invariant features, the framework can be applied in a wide variety of image contexts, in order to study the commonality of anatomical parts or to group subjects according to the parts they share. Experimentation shows that a parts-based model can be learned from a large set of MR brain images, and used to determine parts that are common within the group of subjects. Preliminary results indicate that the model can be used to automatically identify distinctive features for inter-subject image registration despite large changes in appearance.

The influence of temperature pH and water immersion on the high hydrostatic pressure inactivation of GI.1 and GII.4 human noroviruses

USDA-ARS?s Scientific Manuscript database

Detection of human norovirus (HuNoV) usually relies on molecular biology techniques, such as qRT PCR. Since histo-blood group antigens (HBGAs) are the functional receptors for HuNoV, HuNoV can bind to porcine gastric mucin (PGM), which contains HBGA-like antigens. In this study, PGM conjugated magn...

International Workshop on Neuroimmunomodulation (2nd) Held in Dubrovnik (Yugoslavia) on 1-6 June 1986.

DTIC Science & Technology

1986-09-18

systemically with doses of reaction) were sharply reduced. Histo- naltrexone or naloxone and subsequently logically, the infiltration of the dermis...challenged with a lethal dose of antigen. with polymorphonuclear (Arthus reaction) Both naloxone and naltrexone were found and mononuclear cells (delayed...for Integrative Biomedical Research, Eb- roendocrine cell type present in low num- matingen, Switzerland) reported on the bers in the spleen, lymph

Bio-inspired Armor Protective Material Systems for Ballistic Shock Mitigation

DTIC Science & Technology

2011-01-01

Coupon testing a b s t r a c t Severe transient ballistic shocks from projectile impacts, mine blasts , or overhead artillery attacks can incapacitate an...past two decades [1]. A ballistic shock results from a significant amount of concentrated energy deposited from caliber projectile impacts, mine blasts ...LS- Dyna , has been predominately utilized to calculate the target shock responses including acceleration histo- ries, shock response spectra

Results of histo-pathologic examination of three enucleated eyes with a choroidal melanoma after strontium-90 irradiation.

PubMed

Parys-van Ginderdeuren, R; van den Oord, J J; Missotten, L

1997-01-01

Three patients with a choroidal melanoma, treated with HDR (High Dose Rate) Strontium-90 brachytherapy, underwent an enucleation. Radiation effect was only visible at the irradiation zone with a brisk transition to normal tissue. Tumour was replaced by necrotic and scar tissue. The underlying sclera had a markedly reduced number of fibrocytes, but no structural alteration of the collagen stroma.

Spatiotemporal progression of metastatic breast cancer: a Markov chain model highlighting the role of early metastatic sites

PubMed Central

Newton, Paul K; Mason, Jeremy; Venkatappa, Neethi; Jochelson, Maxine S; Hurt, Brian; Nieva, Jorge; Comen, Elizabeth; Norton, Larry; Kuhn, Peter

2015-01-01

Background: Cancer cell migration patterns are critical for understanding metastases and clinical evolution. Breast cancer spreads from one organ system to another via hematogenous and lymphatic routes. Although patterns of spread may superficially seem random and unpredictable, we explored the possibility that this is not the case. Aims: Develop a Markov based model of breast cancer progression that has predictive capability. Methods: On the basis of a longitudinal data set of 446 breast cancer patients, we created a Markov chain model of metastasis that describes the probabilities of metastasis occurring at a given anatomic site together with the probability of spread to additional sites. Progression is modeled as a random walk on a directed graph, where nodes represent anatomical sites where tumors can develop. Results: We quantify how survival depends on the location of the first metastatic site for different patient subcategories. In addition, we classify metastatic sites as “sponges” or “spreaders” with implications regarding anatomical pathway prediction and long-term survival. As metastatic tumors to the bone (main spreader) are most prominent, we focus in more detail on differences between groups of patients who form subsequent metastases to the lung as compared with the liver. Conclusions: We have found that spatiotemporal patterns of metastatic spread in breast cancer are neither random nor unpredictable. Furthermore, the novel concept of classifying organ sites as sponges or spreaders may motivate experiments seeking a biological basis for these phenomena and allow us to quantify the potential consequences of therapeutic targeting of sites in the oligometastatic setting and shed light on organotropic aspects of the disease. PMID:28721371

VirtualDose: a software for reporting organ doses from CT for adult and pediatric patients.

PubMed

Ding, Aiping; Gao, Yiming; Liu, Haikuan; Caracappa, Peter F; Long, Daniel J; Bolch, Wesley E; Liu, Bob; Xu, X George

2015-07-21

This paper describes the development and testing of VirtualDose--a software for reporting organ doses for adult and pediatric patients who undergo x-ray computed tomography (CT) examinations. The software is based on a comprehensive database of organ doses derived from Monte Carlo (MC) simulations involving a library of 25 anatomically realistic phantoms that represent patients of different ages, body sizes, body masses, and pregnant stages. Models of GE Lightspeed Pro 16 and Siemens SOMATOM Sensation 16 scanners were carefully validated for use in MC dose calculations. The software framework is designed with the 'software as a service (SaaS)' delivery concept under which multiple clients can access the web-based interface simultaneously from any computer without having to install software locally. The RESTful web service API also allows a third-party picture archiving and communication system software package to seamlessly integrate with VirtualDose's functions. Software testing showed that VirtualDose was compatible with numerous operating systems including Windows, Linux, Apple OS X, and mobile and portable devices. The organ doses from VirtualDose were compared against those reported by CT-Expo and ImPACT-two dosimetry tools that were based on the stylized pediatric and adult patient models that were known to be anatomically simple. The organ doses reported by VirtualDose differed from those reported by CT-Expo and ImPACT by as much as 300% in some of the patient models. These results confirm the conclusion from past studies that differences in anatomical realism offered by stylized and voxel phantoms have caused significant discrepancies in CT dose estimations.

Applications of 3D printing in the management of severe spinal conditions.

PubMed

Provaggi, Elena; Leong, Julian J H; Kalaskar, Deepak M

2017-06-01

The latest and fastest-growing innovation in the medical field has been the advent of three-dimensional printing technologies, which have recently seen applications in the production of low-cost, patient-specific medical implants. While a wide range of three-dimensional printing systems has been explored in manufacturing anatomical models and devices for the medical setting, their applications are cutting-edge in the field of spinal surgery. This review aims to provide a comprehensive overview and classification of the current applications of three-dimensional printing technologies in spine care. Although three-dimensional printing technology has been widely used for the construction of patient-specific anatomical models of the spine and intraoperative guide templates to provide personalized surgical planning and increase pedicle screw placement accuracy, only few studies have been focused on the manufacturing of spinal implants. Therefore, three-dimensional printed custom-designed intervertebral fusion devices, artificial vertebral bodies and disc substitutes for total disc replacement, along with tissue engineering strategies focused on scaffold constructs for bone and cartilage regeneration, represent a set of promising applications towards the trend of individualized patient care.

Levofloxacin-loaded star poly(ε-caprolactone) scaffolds by additive manufacturing.

PubMed

Puppi, Dario; Piras, Anna Maria; Pirosa, Alessandro; Sandreschi, Stefania; Chiellini, Federica

2016-03-01

The employment of a tissue engineering scaffold able to release an antimicrobial agent with a controlled kinetics represents an effective tool for the treatment of infected tissue defects as well as for the prevention of scaffolds implantation-related infectious complications. This research activity was aimed at the development of additively manufactured star poly(ε-caprolactone) (*PCL) scaffolds loaded with levofloxacin, investigated as antimicrobial fluoroquinolone model. For this purpose a computer-aided wet-spinning technique allowing functionalizing the scaffold during the fabrication process was explored. Scaffolds with customized composition, microstructure and anatomical external shape were developed by optimizing the processing parameters. Morphological, thermal and mechanical characterization showed that drug loading did not compromise the fabrication process and the final performance of the scaffolds. The developed *PCL scaffolds showed a sustained in vitro release of the loaded antibiotic for 5 weeks. The proposed computer-aided wet-spinning technique appears well suited for the fabrication of anatomical scaffolds endowed with levofloxacin-releasing properties to be tested in vivo for the regeneration of long bone critical size defects in a rabbit model.

A graph-based approach for the retrieval of multi-modality medical images.

PubMed

Kumar, Ashnil; Kim, Jinman; Wen, Lingfeng; Fulham, Michael; Feng, Dagan

2014-02-01

In this paper, we address the retrieval of multi-modality medical volumes, which consist of two different imaging modalities, acquired sequentially, from the same scanner. One such example, positron emission tomography and computed tomography (PET-CT), provides physicians with complementary functional and anatomical features as well as spatial relationships and has led to improved cancer diagnosis, localisation, and staging. The challenge of multi-modality volume retrieval for cancer patients lies in representing the complementary geometric and topologic attributes between tumours and organs. These attributes and relationships, which are used for tumour staging and classification, can be formulated as a graph. It has been demonstrated that graph-based methods have high accuracy for retrieval by spatial similarity. However, naïvely representing all relationships on a complete graph obscures the structure of the tumour-anatomy relationships. We propose a new graph structure derived from complete graphs that structurally constrains the edges connected to tumour vertices based upon the spatial proximity of tumours and organs. This enables retrieval on the basis of tumour localisation. We also present a similarity matching algorithm that accounts for different feature sets for graph elements from different imaging modalities. Our method emphasises the relationships between a tumour and related organs, while still modelling patient-specific anatomical variations. Constraining tumours to related anatomical structures improves the discrimination potential of graphs, making it easier to retrieve similar images based on tumour location. We evaluated our retrieval methodology on a dataset of clinical PET-CT volumes. Our results showed that our method enabled the retrieval of multi-modality images using spatial features. Our graph-based retrieval algorithm achieved a higher precision than several other retrieval techniques: gray-level histograms as well as state-of-the-art methods such as visual words using the scale- invariant feature transform (SIFT) and relational matrices representing the spatial arrangements of objects. Copyright © 2013 Elsevier B.V. All rights reserved.

Modeling functional neuroanatomy for an anatomy information system.

PubMed

Niggemann, Jörg M; Gebert, Andreas; Schulz, Stefan

2008-01-01

Existing neuroanatomical ontologies, databases and information systems, such as the Foundational Model of Anatomy (FMA), represent outgoing connections from brain structures, but cannot represent the "internal wiring" of structures and as such, cannot distinguish between different independent connections from the same structure. Thus, a fundamental aspect of Neuroanatomy, the functional pathways and functional systems of the brain such as the pupillary light reflex system, is not adequately represented. This article identifies underlying anatomical objects which are the source of independent connections (collections of neurons) and uses these as basic building blocks to construct a model of functional neuroanatomy and its functional pathways. The basic representational elements of the model are unnamed groups of neurons or groups of neuron segments. These groups, their relations to each other, and the relations to the objects of macroscopic anatomy are defined. The resulting model can be incorporated into the FMA. The capabilities of the presented model are compared to the FMA and the Brain Architecture Management System (BAMS). Internal wiring as well as functional pathways can correctly be represented and tracked. This model bridges the gap between representations of single neurons and their parts on the one hand and representations of spatial brain structures and areas on the other hand. It is capable of drawing correct inferences on pathways in a nervous system. The object and relation definitions are related to the Open Biomedical Ontology effort and its relation ontology, so that this model can be further developed into an ontology of neuronal functional systems.

Extending the knowledge in histochemistry and cell biology.

PubMed

Heupel, Wolfgang-Moritz; Drenckhahn, Detlev

2010-01-01

Central to modern Histochemistry and Cell Biology stands the need for visualization of cellular and molecular processes. In the past several years, a variety of techniques has been achieved bridging traditional light microscopy, fluorescence microscopy and electron microscopy with powerful software-based post-processing and computer modeling. Researchers now have various tools available to investigate problems of interest from bird's- up to worm's-eye of view, focusing on tissues, cells, proteins or finally single molecules. Applications of new approaches in combination with well-established traditional techniques of mRNA, DNA or protein analysis have led to enlightening and prudent studies which have paved the way toward a better understanding of not only physiological but also pathological processes in the field of cell biology. This review is intended to summarize articles standing for the progress made in "histo-biochemical" techniques and their manifold applications.

Computation of high-resolution SAR distributions in a head due to a radiating dipole antenna representing a hand-held mobile phone.

PubMed

Van de Kamer, J B; Lagendijk, J J W

2002-05-21

SAR distributions in a healthy female adult head as a result of a radiating vertical dipole antenna (frequency 915 MHz) representing a hand-held mobile phone have been computed for three different resolutions: 2 mm, 1 mm and 0.4 mm. The extremely high resolution of 0.4 mm was obtained with our quasistatic zooming technique, which is briefly described in this paper. For an effectively transmitted power of 0.25 W, the maximum averaged SAR values in both cubic- and arbitrary-shaped volumes are, respectively, about 1.72 and 2.55 W kg(-1) for 1 g and 0.98 and 1.73 W kg(-1) for 10 g of tissue. These numbers do not vary much (<8%) for the different resolutions, indicating that SAR computations at a resolution of 2 mm are sufficiently accurate to describe the large-scale distribution. However, considering the detailed SAR pattern in the head, large differences may occur if high-resolution computations are performed rather than low-resolution ones. These deviations are caused by both increased modelling accuracy and improved anatomical description in higher resolution simulations. For example, the SAR profile across a boundary between tissues with high dielectric contrast is much more accurately described at higher resolutions. Furthermore, low-resolution dielectric geometries may suffer from loss of anatomical detail, which greatly affects small-scale SAR distributions. Thus. for strongly inhomogeneous regions high-resolution SAR modelling is an absolute necessity.

Modelling and Manufacturing of a 3D Printed Trachea for Cricothyroidotomy Simulation.

PubMed

Doucet, Gregory; Ryan, Stephen; Bartellas, Michael; Parsons, Michael; Dubrowski, Adam; Renouf, Tia

2017-08-18

Cricothyroidotomy is a life-saving medical procedure that allows for tracheal intubation. Most current cricothyroidotomy simulation models are either expensive or not anatomically accurate and provide the learner with an unrealistic simulation experience. The goal of this project is to improve current simulation techniques by utilizing rapid prototyping using 3D printing technology and expert opinions to develop inexpensive and anatomically accurate trachea simulators. In doing so, emergency cricothyroidotomy simulation can be made accessible, accurate, cost-effective and reproducible. Three-dimensional modelling software was used in conjunction with a desktop three-dimensional (3D) printer to design and manufacture an anatomically accurate model of the cartilage within the trachea (thyroid cartilage, cricoid cartilage, and the tracheal rings). The initial design was based on dimensions found in studies of tracheal anatomical configuration. This ensured that the landmarking necessary for emergency cricothyroidotomies was designed appropriately. Several revisions of the original model were made based on informal opinion from medical professionals to establish appropriate anatomical accuracy of the model for use in rural/remote cricothyroidotomy simulation. Using an entry-level desktop 3D printer, a low cost tracheal model was successfully designed that can be printed in less than three hours for only $1.70 Canadian dollars (CAD). Due to its anatomical accuracy, flexibility and durability, this model is great for use in emergency medicine simulation training. Additionally, the model can be assembled in conjunction with a membrane to simulate tracheal ligaments. Skin has been simulated as well to enhance the realism of the model. The result is an accurate simulation that will provide users with an anatomically correct model to practice important skills used in emergency airway surgery, specifically landmarking, incision and intubation. This design is a novel and easy to manufacture and reproduce, high fidelity trachea model that can be used by educators with limited resources.

Modelling and Manufacturing of a 3D Printed Trachea for Cricothyroidotomy Simulation

PubMed Central

Ryan, Stephen; Bartellas, Michael; Parsons, Michael; Dubrowski, Adam; Renouf, Tia

2017-01-01

Cricothyroidotomy is a life-saving medical procedure that allows for tracheal intubation. Most current cricothyroidotomy simulation models are either expensive or not anatomically accurate and provide the learner with an unrealistic simulation experience. The goal of this project is to improve current simulation techniques by utilizing rapid prototyping using 3D printing technology and expert opinions to develop inexpensive and anatomically accurate trachea simulators. In doing so, emergency cricothyroidotomy simulation can be made accessible, accurate, cost-effective and reproducible. Three-dimensional modelling software was used in conjunction with a desktop three-dimensional (3D) printer to design and manufacture an anatomically accurate model of the cartilage within the trachea (thyroid cartilage, cricoid cartilage, and the tracheal rings). The initial design was based on dimensions found in studies of tracheal anatomical configuration. This ensured that the landmarking necessary for emergency cricothyroidotomies was designed appropriately. Several revisions of the original model were made based on informal opinion from medical professionals to establish appropriate anatomical accuracy of the model for use in rural/remote cricothyroidotomy simulation. Using an entry-level desktop 3D printer, a low cost tracheal model was successfully designed that can be printed in less than three hours for only $1.70 Canadian dollars (CAD). Due to its anatomical accuracy, flexibility and durability, this model is great for use in emergency medicine simulation training. Additionally, the model can be assembled in conjunction with a membrane to simulate tracheal ligaments. Skin has been simulated as well to enhance the realism of the model. The result is an accurate simulation that will provide users with an anatomically correct model to practice important skills used in emergency airway surgery, specifically landmarking, incision and intubation. This design is a novel and easy to manufacture and reproduce, high fidelity trachea model that can be used by educators with limited resources. PMID:29057187

Experimental validation of finite element modelling of a modular metal-on-polyethylene total hip replacement.

PubMed

Hua, Xijin; Wang, Ling; Al-Hajjar, Mazen; Jin, Zhongmin; Wilcox, Ruth K; Fisher, John

2014-07-01

Finite element models are becoming increasingly useful tools to conduct parametric analysis, design optimisation and pre-clinical testing for hip joint replacements. However, the verification of the finite element model is critically important. The purposes of this study were to develop a three-dimensional anatomic finite element model for a modular metal-on-polyethylene total hip replacement for predicting its contact mechanics and to conduct experimental validation for a simple finite element model which was simplified from the anatomic finite element model. An anatomic modular metal-on-polyethylene total hip replacement model (anatomic model) was first developed and then simplified with reasonable accuracy to a simple modular total hip replacement model (simplified model) for validation. The contact areas on the articulating surface of three polyethylene liners of modular metal-on-polyethylene total hip replacement bearings with different clearances were measured experimentally in the Leeds ProSim hip joint simulator under a series of loading conditions and different cup inclination angles. The contact areas predicted from the simplified model were then compared with that measured experimentally under the same conditions. The results showed that the simplification made for the anatomic model did not change the predictions of contact mechanics of the modular metal-on-polyethylene total hip replacement substantially (less than 12% for contact stresses and contact areas). Good agreements of contact areas between the finite element predictions from the simplified model and experimental measurements were obtained, with maximum difference of 14% across all conditions considered. This indicated that the simplification and assumptions made in the anatomic model were reasonable and the finite element predictions from the simplified model were valid. © IMechE 2014.

Identification and Targeting of Candidate Pre-Existing Lurker Cells that Give Rise to Castration-Resistant Prostate Cancer

DTIC Science & Technology

2014-10-01

carcinoma with different signaling pathways characteristic of each histo- logical pattern. eIF4E-driven protein translation pathway is el - evated in...and 4EBP1 ( Epitomics ); Histone H3, AKT, and p4EBP1 (Thr37/46); pErk1/ 2 (T202/Y204), pSTAT3 (Y705), Sox2, MTA1, Src, and pSrc (Y416) (Cell Signaling

Merced County Streams Project, California Intensive Cultural Resources Survey (Downstream Channel Improvements).

DTIC Science & Technology

1982-03-01

subsurface structure. IN SITU : In place; a term applied to archeological phenomena which are found in their original, undisturbed position or location...etal material found in excavation be covered back over and that the grave goods remain with the body. They are usually willing that in situ ...Merced area, California. Government Printing Office, Washington, D.i. Wood, Raymond F. 1954 California’s Agua Fria: the early histo-/ of Mariposa

Development of an Anatomically Accurate Finite Element Human Ocular Globe Model for Blast-Related Fluid-Structure Interaction Studies

DTIC Science & Technology

2017-02-01

ARL-TR-7945 ● FEB 2017 US Army Research Laboratory Development of an Anatomically Accurate Finite Element Human Ocular Globe...ARL-TR-7945 ● FEB 2017 US Army Research Laboratory Development of an Anatomically Accurate Finite Element Human Ocular Globe Model... Finite Element Human Ocular Globe Model for Blast-Related Fluid-Structure Interaction Studies 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM

X-ray computed tomography library of shark anatomy and lower jaw surface models.

PubMed

Kamminga, Pepijn; De Bruin, Paul W; Geleijns, Jacob; Brazeau, Martin D

2017-04-11

The cranial diversity of sharks reflects disparate biomechanical adaptations to feeding. In order to be able to investigate and better understand the ecomorphology of extant shark feeding systems, we created a x-ray computed tomography (CT) library of shark cranial anatomy with three-dimensional (3D) lower jaw reconstructions. This is used to examine and quantify lower jaw disparity in extant shark species in a separate study. The library is divided in a dataset comprised of medical CT scans of 122 sharks (Selachimorpha, Chondrichthyes) representing 73 extant species, including digitized morphology of entire shark specimens. This CT dataset and additional data provided by other researchers was used to reconstruct a second dataset containing 3D models of the left lower jaw for 153 individuals representing 94 extant shark species. These datasets form an extensive anatomical record of shark skeletal anatomy, necessary for comparative morphological, biomechanical, ecological and phylogenetic studies.

Animal models of female pelvic organ prolapse: lessons learned

PubMed Central

Couri, Bruna M; Lenis, Andrew T; Borazjani, Ali; Paraiso, Marie Fidela R; Damaser, Margot S

2012-01-01

Pelvic organ prolapse is a vaginal protrusion of female pelvic organs. It has high prevalence worldwide and represents a great burden to the economy. The pathophysiology of pelvic organ prolapse is multifactorial and includes genetic predisposition, aberrant connective tissue, obesity, advancing age, vaginal delivery and other risk factors. Owing to the long course prior to patients becoming symptomatic and ethical questions surrounding human studies, animal models are necessary and useful. These models can mimic different human characteristics – histological, anatomical or hormonal, but none present all of the characteristics at the same time. Major animal models include knockout mice, rats, sheep, rabbits and nonhuman primates. In this article we discuss different animal models and their utility for investigating the natural progression of pelvic organ prolapse pathophysiology and novel treatment approaches. PMID:22707980

Regional myocardial flow heterogeneity explained with fractal networks

PubMed Central

VAN BEEK, JOHANNES H. G. M.; ROGER, STEPHEN A.; BASSINGTHWAIGHTE, JAMES B.

2010-01-01

There is explain how the distribution of flow broadens with an increase in the spatial resolution of the measurement, we developed fractal models for vascular networks. A dichotomous branching network of vessels represents the arterial tree and connects to a similar venous network. A small difference in vessel lengths and radii between the two daughter vessels, with the same degree of asymmetry at each branch generation, predicts the dependence of the relative dispersion (mean ± SD) on spatial resolution of the perfusion measurement reasonably well. When the degree of asymmetry increases with successive branching, a better fit to data on sheep and baboons results. When the asymmetry is random, a satisfactory fit is found. These models show that a difference in flow of 20% between the daughter vessels at a branch point gives a relative dispersion of flow of ~30% when the heart is divided into 100–200 pieces. Although these simple models do not represent anatomic features accurately, they provide valuable insight on the heterogeneity of flow within the heart. PMID:2589520

The CLAIR model: Extension of Brodmann areas based on brain oscillations and connectivity.

PubMed

Başar, Erol; Düzgün, Aysel

2016-05-01

Since the beginning of the last century, the localization of brain function has been represented by Brodmann areas, maps of the anatomic organization of the brain. They are used to broadly represent cortical structures with their given sensory-cognitive functions. In recent decades, the analysis of brain oscillations has become important in the correlation of brain functions. Moreover, spectral connectivity can provide further information on the dynamic connectivity between various structures. In addition, brain responses are dynamic in nature and structural localization is almost impossible, according to Luria (1966). Therefore, brain functions are very difficult to localize; hence, a combined analysis of oscillation and event-related coherences is required. In this study, a model termed as "CLAIR" is described to enrich and possibly replace the concept of the Brodmann areas. A CLAIR model with optimum function may take several years to develop, but this study sets out to lay its foundation. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Use of a 3D Skull Model to Improve Accuracy in Cranioplasty for Autologous Flap Resorption in a 3-Year-Old Child.

PubMed

Maduri, Rodolfo; Viaroli, Edoardo; Levivier, Marc; Daniel, Roy T; Messerer, Mahmoud

2017-01-01

Cranioplasty is considered a simple reconstructive procedure, usually performed in a single stage. In some clinical conditions, such as in children with multifocal flap osteolysis, it could represent a surgical challenge. In these patients, the partially resorbed autologous flap should be removed and replaced with a precustomed prosthesis which should perfectly match the expected bone defect. We describe the technique used for a navigated cranioplasty in a 3-year-old child with multifocal autologous flap osteolysis. We decided to perform a cranioplasty using a custom-made hydroxyapatite porous ceramic flap. The prosthesis was produced with an epoxy resin 3D skull model of the patient, which included a removable flap corresponding to the planned cranioplasty. Preoperatively, a CT scan of the 3D skull model was performed without the removable flap. The CT scan images of the 3D skull model were merged with the preoperative 3D CT scan of the patient and navigated during the cranioplasty to define with precision the cranioplasty margins. After removal of the autologous resorbed flap, the hydroxyapatite prosthesis matched perfectly with the skull defect. The anatomical result was excellent. Thus, the implementation of cranioplasty with image merge navigation of a 3D skull model may improve cranioplasty accuracy, allowing precise anatomic reconstruction in complex skull defect cases. © 2017 S. Karger AG, Basel.

VirtualDose: a software for reporting organ doses from CT for adult and pediatric patients

NASA Astrophysics Data System (ADS)

Ding, Aiping; Gao, Yiming; Liu, Haikuan; Caracappa, Peter F.; Long, Daniel J.; Bolch, Wesley E.; Liu, Bob; Xu, X. George

2015-07-01

This paper describes the development and testing of VirtualDose—a software for reporting organ doses for adult and pediatric patients who undergo x-ray computed tomography (CT) examinations. The software is based on a comprehensive database of organ doses derived from Monte Carlo (MC) simulations involving a library of 25 anatomically realistic phantoms that represent patients of different ages, body sizes, body masses, and pregnant stages. Models of GE Lightspeed Pro 16 and Siemens SOMATOM Sensation 16 scanners were carefully validated for use in MC dose calculations. The software framework is designed with the ‘software as a service (SaaS)’ delivery concept under which multiple clients can access the web-based interface simultaneously from any computer without having to install software locally. The RESTful web service API also allows a third-party picture archiving and communication system software package to seamlessly integrate with VirtualDose’s functions. Software testing showed that VirtualDose was compatible with numerous operating systems including Windows, Linux, Apple OS X, and mobile and portable devices. The organ doses from VirtualDose were compared against those reported by CT-Expo and ImPACT—two dosimetry tools that were based on the stylized pediatric and adult patient models that were known to be anatomically simple. The organ doses reported by VirtualDose differed from those reported by CT-Expo and ImPACT by as much as 300% in some of the patient models. These results confirm the conclusion from past studies that differences in anatomical realism offered by stylized and voxel phantoms have caused significant discrepancies in CT dose estimations.

Prerequisites of realization of total breast reconstruction concept in Tomsk region

NASA Astrophysics Data System (ADS)

Dudnikov, A.; Smirnov, N.; Belozertseva, A.; Baitinger, A.; Kudyakov, L.

2015-11-01

The recent research represents the attempt of economical evaluation of the Total Breast Reconstruction concept (TBR), which was formulated in «Scientific and Research Institute of Microsurgery», in 2014. This concept includes anatomical and functional breast reconstruction, afferential reinnervation, sensitivity recovery and the creation of a new erogenous zone in the reconstructed breast. The created clinical-economical model allows for the evaluation of the efficacy and benefits of using the TBR concept. The benefits of using TBR concept for Tomsk Region also were evaluated.

Take away body parts! An investigation into the use of 3D-printed anatomical models in undergraduate anatomy education.

PubMed

Smith, Claire F; Tollemache, Nicholas; Covill, Derek; Johnston, Malcolm

2018-01-01

Understanding the three-dimensional (3D) nature of the human form is imperative for effective medical practice and the emergence of 3D printing creates numerous opportunities to enhance aspects of medical and healthcare training. A recently deceased, un-embalmed donor was scanned through high-resolution computed tomography. The scan data underwent segmentation and post-processing and a range of 3D-printed anatomical models were produced. A four-stage mixed-methods study was conducted to evaluate the educational value of the models in a medical program. (1) A quantitative pre/post-test to assess change in learner knowledge following 3D-printed model usage in a small group tutorial; (2) student focus group (3) a qualitative student questionnaire regarding personal student model usage (4) teaching faculty evaluation. The use of 3D-printed models in small-group anatomy teaching session resulted in a significant increase in knowledge (P = 0.0001) when compared to didactic 2D-image based teaching methods. Student focus groups yielded six key themes regarding the use of 3D-printed anatomical models: model properties, teaching integration, resource integration, assessment, clinical imaging, and pathology and anatomical variation. Questionnaires detailed how students used the models in the home environment and integrated them with anatomical learning resources such as textbooks and anatomy lectures. In conclusion, 3D-printed anatomical models can be successfully produced from the CT data set of a recently deceased donor. These models can be used in anatomy education as a teaching tool in their own right, as well as a method for augmenting the curriculum and complementing established learning modalities, such as dissection-based teaching. Anat Sci Educ 11: 44-53. © 2017 American Association of Anatomists. © 2017 American Association of Anatomists.

[The periosteum: the "umbilical cord" of bone. Quantification of the blood supply of cortical bone of periosteal origin].

PubMed

Chanavaz, M

1995-01-01

The Periosteum or periosteal membrane is a continuous composite fibroelastic covering membrane of the bone to which it is intimately linked. It consists of multipotent mesodermal cells (11, 15). Although the bone cortex is the main beneficiary of the principal anatomical and physiological functions of the periosteal membrane, the behaviour of the entire bone remains closely influenced by the periosteal activity. These principal functions are related to the cortical blood supply, osteogenesis, muscle and ligament attachments. Through its elastic and contractile nature, it participates in the maintenance of bone shape, and plays an important role in metabolic ionic exchange and physiological distribution of electro-chemical potential difference across its membranous structure. It has also been suggested that the periosteum may have its own specific proprioceptive property. This presentation will study the histo-anatomy and physiology of the periosteum and will discuss in detail its main functions of cortical blood supply and osteogenesis (fig. 1 and 2). It will also present the third intermediary report on a current study of the quantification of cortical vascularisation of femoral bone via the periosteum, using an isotonic salt solution of 85Strontium. The afferent-efferent (arterio-venous) flows of this solution in the thigh vascular system of guinea pigs were measured by gamma spectrometry after a series of selective macro and micro injections of radioactive salt into the femoral arterial system were carried out. Each vascular territory was meticulously selected and the injections were made according to size, starting with the larger vessels, with or without ligatures of neighbouring vessels, going progressively to smaller and smaller vessels not exceeding 100m in diameter.(ABSTRACT TRUNCATED AT 250 WORDS)

A Mock Circulatory System Incorporating a Compliant 3D-Printed Anatomical Model to Investigate Pulmonary Hemodynamics.

PubMed

Knoops, Paul G M; Biglino, Giovanni; Hughes, Alun D; Parker, Kim H; Xu, Linzhang; Schievano, Silvia; Torii, Ryo

2017-07-01

A realistic mock circulatory system (MCS) could be a valuable in vitro testbed to study human circulatory hemodynamics. The objective of this study was to design a MCS replicating the pulmonary arterial circulation, incorporating an anatomically representative arterial model suitable for testing clinically relevant scenarios. A second objective of the study was to ensure the system's compatibility with magnetic resonance imaging (MRI) for additional measurements. A latex pulmonary arterial model with two generations of bifurcations was manufactured starting from a 3D-printed mold reconstructed from patient data. The model was incorporated into a MCS for in vitro hydrodynamic measurements. The setup was tested under physiological pulsatile flow conditions and results were evaluated using wave intensity analysis (WIA) to investigate waves traveling in the arterial system. Increased pulmonary vascular resistance (IPVR) was simulated as an example of one pathological scenario. Flow split between right and left pulmonary artery was found to be realistic (54 and 46%, respectively). No substantial difference in pressure waveform was observed throughout the various generations of bifurcations. Based on WIA, three main waves were identified in the main pulmonary artery (MPA), that is, forward compression wave, backward compression wave, and forward expansion wave. For IPVR, a rise in mean pressure was recorded in the MPA, within the clinical range of pulmonary arterial hypertension. The feasibility of using the MCS in the MRI scanner was demonstrated with the MCS running 2 h consecutively while acquiring preliminary MRI data. This study shows the development and verification of a pulmonary MCS, including an anatomically correct, compliant latex phantom. The setup can be useful to explore a wide range of hemodynamic questions, including the development of patient- and pathology-specific models, considering the ease and low cost of producing rapid prototyping molds, and the versatility of the setup for invasive and noninvasive (i.e., MRI) measurements. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

A Mock Circulatory System Incorporating a Compliant 3D-Printed Anatomical Model to Investigate Pulmonary Hemodynamics

PubMed Central

Knoops, Paul G.M.; Biglino, Giovanni; Hughes, Alun D.; Parker, Kim H.; Xu, Linzhang; Schievano, Silvia; Torii, Ryo

2017-01-01

A realistic mock circulatory system (MCS) could be a valuable in vitro testbed to study human circulatory hemodynamics. The objective of this study was to design a MCS replicating the pulmonary arterial circulation, incorporating an anatomically representative arterial model suitable for testing clinically relevant scenarios. A second objective of the study was to ensure the system's compatibility with magnetic resonance imaging (MRI) for additional measurements. A latex pulmonary arterial model with two generations of bifurcations was manufactured starting from a 3D-printed mold reconstructed from patient data. The model was incorporated into a MCS for in vitro hydrodynamic measurements. The setup was tested under physiological pulsatile flow conditions and results were evaluated using wave intensity analysis (WIA) to investigate waves traveling in the arterial system. Increased pulmonary vascular resistance (IPVR) was simulated as an example of one pathological scenario. Flow split between right and left pulmonary artery was found to be realistic (54 and 46%, respectively). No substantial difference in pressure waveform was observed throughout the various generations of bifurcations. Based on WIA, three main waves were identified in the main pulmonary artery (MPA), that is, forward compression wave, backward compression wave, and forward expansion wave. For IPVR, a rise in mean pressure was recorded in the MPA, within the clinical range of pulmonary arterial hypertension. The feasibility of using the MCS in the MRI scanner was demonstrated with the MCS running 2 h consecutively while acquiring preliminary MRI data. This study shows the development and verification of a pulmonary MCS, including an anatomically correct, compliant latex phantom. The setup can be useful to explore a wide range of hemodynamic questions, including the development of patient- and pathology-specific models, considering the ease and low cost of producing rapid prototyping molds, and the versatility of the setup for invasive and noninvasive (i.e., MRI) measurements. PMID:27925228

Modeling Functional Neuroanatomy for an Anatomy Information System

PubMed Central

Niggemann, Jörg M.; Gebert, Andreas; Schulz, Stefan

2008-01-01

Objective Existing neuroanatomical ontologies, databases and information systems, such as the Foundational Model of Anatomy (FMA), represent outgoing connections from brain structures, but cannot represent the “internal wiring” of structures and as such, cannot distinguish between different independent connections from the same structure. Thus, a fundamental aspect of Neuroanatomy, the functional pathways and functional systems of the brain such as the pupillary light reflex system, is not adequately represented. This article identifies underlying anatomical objects which are the source of independent connections (collections of neurons) and uses these as basic building blocks to construct a model of functional neuroanatomy and its functional pathways. Design The basic representational elements of the model are unnamed groups of neurons or groups of neuron segments. These groups, their relations to each other, and the relations to the objects of macroscopic anatomy are defined. The resulting model can be incorporated into the FMA. Measurements The capabilities of the presented model are compared to the FMA and the Brain Architecture Management System (BAMS). Results Internal wiring as well as functional pathways can correctly be represented and tracked. Conclusion This model bridges the gap between representations of single neurons and their parts on the one hand and representations of spatial brain structures and areas on the other hand. It is capable of drawing correct inferences on pathways in a nervous system. The object and relation definitions are related to the Open Biomedical Ontology effort and its relation ontology, so that this model can be further developed into an ontology of neuronal functional systems. PMID:18579841

Fabrication and Assessment of 3D Printed Anatomical Models of the Lower Limb for Anatomical Teaching and Femoral Vessel Access Training in Medicine

ERIC Educational Resources Information Center

O'Reilly, Michael K.; Reese, Sven; Herlihy, Therese; Geoghegan, Tony; Cantwell, Colin P.; Feeney, Robin N. M.; Jones, James F. X.

2016-01-01

For centuries, cadaveric dissection has been the touchstone of anatomy education. It offers a medical student intimate access to his or her first patient. In contrast to idealized artisan anatomical models, it presents the natural variation of anatomy in fine detail. However, a new teaching construct has appeared recently in which artificial…

Operation UPSHOT-KNOTHOLE. Operational Summary, Nevada Proving Grounds, 1 March - 9 June 1953

DTIC Science & Technology

1982-08-01

EXTRACTED VERSION OPERATION UPSHOT-KNOTHOLE -- Operational Summary Nevada Proving Grounds ,* 1 March-9 June 1953 Headquarters Field Command Armed...Weapons Effects Tests 9. PERIORUMING 004CAWIZAY10ON AME ANO AOO1RESS 10. P140GRAM ELEMENPT, PROJECT, TASK AREA a 1114.01110 UNIT NUMBERS Headquarters Field ...process of preparation. Activities in prepara- tion for the operational period have been previously recorded in Field Commnand Histo y DO I "’* 1473

Evaluation of the Histo - Gastroprotective and Antimicrobial Activities of Heliotropium Indicum Linn (Boraginaceae)

PubMed Central

Adelaja, Akinlolu Abdulazeez; Ayoola, M. D.; Otulana, J. O.; Akinola, O. B.; Olayiwola, Abimbola; Ejiwunmi, A. B.

2008-01-01

Heliotropium indicum of the family Boraginaceae is used locally in Nigeria to treat ailments such as ulcer and fever. In this study, ulceration of the gastric mucosa in Wistar rats was induced via the oral administration of 80mg/kg/bodyweight of Indomethacin. Histological analyses of the stomach body wall in the rats of Groups 2 and 4 (which received 100mg/kg/bodyweight of extract before oral administration of 80mg/kg/bodyweight Indomethacin and 80mg/kg/bodyweight Indomethacin only respectively) showed erosion of the mucus-secreting cells, gastric pit, upper and middle parts of gastric glands and some of the parietal cells. Histological observations of the stomach body wall in rats of Group 5 (which received 200mg/kg/bodyweight of extract before oral administration of 80mg/kg/bodyweight of Indomethacin) showed erosion of the mucus-secreting cells, gastric pit and the upper most part of the gastric gland. Histological observations of the stomach body wall in rats of Groups 1, 6 and 3 (which received 50mg/kg/bodyweight of Ranitidine and 400mg/kg/bodyweight of extract before oral administration of 80mg/kg/bodyweight Indomethacin; and only 80mg/kg/bodyweight of Normal Saline respectively) showed normal morphological appearance of the different components of the mucosa layer. Thus, the aqueous extracts of the dried leaves of Heliotropium indicum have dose dependent histo-gastroprotective effects. PMID:22570586

Evaluation of the histo - gastroprotective and antimicrobial activities of heliotropium indicum linn (boraginaceae).

PubMed

Adelaja, Akinlolu Abdulazeez; Ayoola, M D; Otulana, J O; Akinola, O B; Olayiwola, Abimbola; Ejiwunmi, A B

2008-07-01

Heliotropium indicum of the family Boraginaceae is used locally in Nigeria to treat ailments such as ulcer and fever. In this study, ulceration of the gastric mucosa in Wistar rats was induced via the oral administration of 80mg/kg/bodyweight of Indomethacin. Histological analyses of the stomach body wall in the rats of Groups 2 and 4 (which received 100mg/kg/bodyweight of extract before oral administration of 80mg/kg/bodyweight Indomethacin and 80mg/kg/bodyweight Indomethacin only respectively) showed erosion of the mucus-secreting cells, gastric pit, upper and middle parts of gastric glands and some of the parietal cells. Histological observations of the stomach body wall in rats of Group 5 (which received 200mg/kg/bodyweight of extract before oral administration of 80mg/kg/bodyweight of Indomethacin) showed erosion of the mucus-secreting cells, gastric pit and the upper most part of the gastric gland. Histological observations of the stomach body wall in rats of Groups 1, 6 and 3 (which received 50mg/kg/bodyweight of Ranitidine and 400mg/kg/bodyweight of extract before oral administration of 80mg/kg/bodyweight Indomethacin; and only 80mg/kg/bodyweight of Normal Saline respectively) showed normal morphological appearance of the different components of the mucosa layer. Thus, the aqueous extracts of the dried leaves of Heliotropium indicum have dose dependent histo-gastroprotective effects.

Distribution, Management Difficulty and Outcome of Branchial Anomalies.

PubMed

Sattar, M A; Sultana, M T; Ahmed, S

2018-01-01

Branchial arch anomalies are one of the most common congenital anomalies of the neck. Developmental anomalies of the branchial apparatus account for 17% of all pediatric cervical masses. This study aimed to focus on proper diagnosis of branchial anomaly and describe occurrence, presentation, management and outcome of usual and unusual types. This ten-year prospective observational study was conducted from November 2005 to November 2015 including 2-year postoperative follow-up of the patients in Department of ENT, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh. Total 89 patients were enrolled for this study. Information was recorded on Clinical examination, relevant investigation, Per-operative findings and Histo-pathological findings. After receiving Histo-pathological findings 61 cases were proved as branchial arch anomalies. Ultrasonography and Histopathology was done for every patient. Fistulogram and sinogram was done for patient of fistula and sinus respectively. CT scan was needed for 9 patients, MRI for 3 patients and 12 patient undergone FNAC. Outcomes of those patients were described in terms of Hospital stay, Complications and Follow up studies. Data analysis was done by Standard Statistical Method.Presentation of a number of participant's mimics Branchial arch anomalies; 4.91% was syndromal. Second branchial arch anomalies were the highest. Management was exclusively surgical. Recurrence rate was about 6.56%. Surgery is the tool for diagnosis, treatment, preventing complications, avoiding carcinoma for branchial arch anomalies.

Cardiac mucosa at the gastro-oesophageal junction: indicator of gastro-oesophageal reflux disease? Data from a prospective central European multicentre study on histological and endoscopic diagnosis of oesophagitis (histoGERD trial).

PubMed

Langner, Cord; Schneider, Nora I; Plieschnegger, Wolfgang; Schmack, Bertram; Bordel, Hartmut; Höfler, Bernd; Eherer, Andreas J; Wolf, Eva-Maria; Rehak, Peter; Vieth, Michael

2014-07-01

The origin and significance of cardiac mucosa at the gastro-oesophageal junction are controversial. In the prospective Central European multicentre histoGERD trial, we aimed to assess the prevalence of cardiac mucosa, characterized by the presence of glands composed of mucous cells without parietal cells, and to relate its presence to features related to gastro-oesophageal reflux disease (GORD). One thousand and seventy-one individuals (576 females and 495 males; median age 53 years) were available for analysis. Overall, in biopsy specimens systematically taken from above and below the gastro-oesophageal junction, cardiac mucosa was observed in 713 (66.6%) individuals. Its presence was associated with patients' symptoms and/or complaints (P = 0.0025), histological changes of the squamous epithelium (P < 0.001) indicative of GORD, intestinal metaplasia (P < 0.001), and an endoscopic diagnosis of oesophagitis (P < 0.001). No association with an endoscopic diagnosis of Barrett's oesophagus or with gastric pathology, particularly Helicobacter infection, was observed. Cardiac mucosa is a common finding in biopsy specimens taken from the gastro-oesophageal junction. Its association with reflux symptoms, histological changes indicating GORD and the endoscopic diagnosis of oesophagitis suggests that injury and repair related to GORD contribute to its development and/or expansion. © 2014 John Wiley & Sons Ltd.

Improved statistical power with a sparse shape model in detecting an aging effect in the hippocampus and amygdala

NASA Astrophysics Data System (ADS)

Chung, Moo K.; Kim, Seung-Goo; Schaefer, Stacey M.; van Reekum, Carien M.; Peschke-Schmitz, Lara; Sutterer, Matthew J.; Davidson, Richard J.

2014-03-01

The sparse regression framework has been widely used in medical image processing and analysis. However, it has been rarely used in anatomical studies. We present a sparse shape modeling framework using the Laplace- Beltrami (LB) eigenfunctions of the underlying shape and show its improvement of statistical power. Tradition- ally, the LB-eigenfunctions are used as a basis for intrinsically representing surface shapes as a form of Fourier descriptors. To reduce high frequency noise, only the first few terms are used in the expansion and higher frequency terms are simply thrown away. However, some lower frequency terms may not necessarily contribute significantly in reconstructing the surfaces. Motivated by this idea, we present a LB-based method to filter out only the significant eigenfunctions by imposing a sparse penalty. For dense anatomical data such as deformation fields on a surface mesh, the sparse regression behaves like a smoothing process, which will reduce the error of incorrectly detecting false negatives. Hence the statistical power improves. The sparse shape model is then applied in investigating the influence of age on amygdala and hippocampus shapes in the normal population. The advantage of the LB sparse framework is demonstrated by showing the increased statistical power.

The ability to mentally represent action is associated with low motor ability in children: a preliminary investigation.

PubMed

Gabbard, Carl; Caçola, Priscila; Bobbio, Tatiana

2012-05-01

Theory and anatomical research suggest that the ability to mentally represent intended actions affect level of execution. This study presents preliminary data examining the association between children's ability to mentally represent action and general motor ability. Children aged 7- to 10 years were assessed for motor imagery ability using a simulation of reach task and motor ability via the Movement ABC-2. Motor ability values, based on percentile rank, ranged from 2 to 91, with a mean of 36. The overall correlation between mental representation and motor ability yielded a moderately positive relationship (r = .39). Interestingly, when looking at motor ability subcategories, only Balance was significant in the model, explaining 20% of the variance. These results provide preliminary evidence that children's motor ability and the ability to mentally represent action are associated in a positive direction. Furthermore, given the results for Balance, we speculate that there are clinical implications regarding work with potentially at-risk children. © 2011 Blackwell Publishing Ltd.

Probabilistic atlas and geometric variability estimation to drive tissue segmentation.

PubMed

Xu, Hao; Thirion, Bertrand; Allassonnière, Stéphanie

2014-09-10

Computerized anatomical atlases play an important role in medical image analysis. While an atlas usually refers to a standard or mean image also called template, which presumably represents well a given population, it is not enough to characterize the observed population in detail. A template image should be learned jointly with the geometric variability of the shapes represented in the observations. These two quantities will in the sequel form the atlas of the corresponding population. The geometric variability is modeled as deformations of the template image so that it fits the observations. In this paper, we provide a detailed analysis of a new generative statistical model based on dense deformable templates that represents several tissue types observed in medical images. Our atlas contains both an estimation of probability maps of each tissue (called class) and the deformation metric. We use a stochastic algorithm for the estimation of the probabilistic atlas given a dataset. This atlas is then used for atlas-based segmentation method to segment the new images. Experiments are shown on brain T1 MRI datasets. Copyright © 2014 John Wiley & Sons, Ltd.

The influence of Staphylococcus aureus on gut microbial ecology in an in vitro continuous culture human colonic model system.

PubMed

Sannasiddappa, Thippeswamy H; Costabile, Adele; Gibson, Glenn R; Clarke, Simon R

2011-01-01

An anaerobic three-stage continuous culture model of the human colon (gut model), which represent different anatomical areas of the large intestine, was used to study the effect of S. aureus infection of the gut on the resident faecal microbiota. Studies on the development of the microbiota in the three vessels were performed and bacteria identified by culture independent fluorescence in situ hybridization (FISH). Furthermore, short chain fatty acids (SCFA), as principal end products of gut bacterial metabolism, were measured along with a quantitative assessment of the predominant microbiota. During steady state conditions, numbers of S. aureus cells stabilised until they were washed out, but populations of indigenous bacteria were transiently altered; thus S. aureus was able to compromise colonisation resistance by the colonic microbiota. Furthermore, the concentration of butyric acid in the vessel representing the proximal colon was significantly decreased by infection. Thus infection by S. aureus appears to be able to alter the overall structure of the human colonic microbiota and the microbial metabolic profiles. This work provides an initial in vitro model to analyse interactions with pathogens.

Characterizing brain patterns in conversion from mild cognitive impairment (MCI) to Alzheimer's disease

NASA Astrophysics Data System (ADS)

Silva R., Santiago S.; Giraldo, Diana L.; Romero, Eduardo

2017-11-01

Structural Magnetic Resonance (MR) brain images should provide quantitative information about the stage and progression of Alzheimer's disease. However, the use of MRI is limited and practically reduced to corroborate a diagnosis already performed with neuropsychological tools. This paper presents an automated strategy for extraction of relevant anatomic patterns related with the conversion from mild cognitive impairment (MCI) to Alzheimer's disease (AD) using T1-weighted MR images. The process starts by representing each of the possible classes with models generated from a linear combination of volumes. The difference between models allows us to establish which are the regions where relevant patterns might be located. The approach searches patterns in a space of brain sulci, herein approximated by the most representative gradients found in regions of interest defined by the difference between the linear models. This hypothesis is assessed by training a conventional SVM model with the found relevant patterns under a leave-one-out scheme. The resultant AUC was 0.86 for the group of women and 0.61 for the group of men.

Age-related changes in thoracic skeletal geometry of elderly females.

PubMed

Holcombe, Sven A; Wang, Stewart C; Grotberg, James B

2017-05-29

Both females and the elderly have been identified as vulnerable populations with increased injury and mortality risk in multiple crash scenarios. Particularly in frontal impacts, older females show higher risk to the chest and thorax than their younger or male counterparts. Thoracic geometry plays a role in this increase, and this study aims to quantify key parts of that geometry in a way that can directly inform human body models that incorporate the concept of person age. Computed tomography scans from 2 female subject groups aged 20-35 and 65-99 were selected from the International Center for Automotive Medicine scan database representing young and old female populations. A model of thoracic skeletal anatomy was built for each subject from independent parametric models of the spine, ribs, and sternum, along with further parametric models of those components' spatial relationships. Parameter values between the 2 groups are directly compared, and average parameter values within each group are used to generate statistically average skeletal geometry for young and old females. In addition to the anatomic measures explicitly used in the parameterization scheme, key measures of rib cage depth and spine curvature are taken from both the underlying subject pool and from the resultant representative geometries. Statistically significant differences were seen between the young and old groups' spine and rib anatomic components, with no significant differences in local sternal geometry found. Vertebral segments in older females had higher angles relative to their inferior neighbors, providing a quantification of the kyphotic curvature known to be associated with age. Ribs in older females had greater end-to-end span, greater aspect ratio, and reduced out-of-plane deviation, producing an elongated and overall flatter curvature that leads to distal rib ends extending further anteriorly in older individuals. Combined differences in spine curvature and rib geometry led to an 18-mm difference in anterior placement of the sternum between young and old subjects. This study provides new geometric data regarding the variability in anthropometry of adult females with age and has utility in advancing the veracity of current human body models. A simplified scaffold representation of underlying 3-dimensional bones within the thorax is presented, and the reported young and old female parameter sets can be used to characterize the anatomic differences expected with age and to both validate and drive morphing algorithms for aged human body models. The modular approach taken allows model parameters to hold inherent and intuitive meaning, offering advantages over more generalized methods such as principal component analysis. Geometry can be assessed on a component level or a whole thorax level, and the parametric representation of thorax shape allows direct comparisons between the current study and other individuals or human body models.

Estimating patient-specific and anatomically correct reference model for craniomaxillofacial deformity via sparse representation

PubMed Central

Wang, Li; Ren, Yi; Gao, Yaozong; Tang, Zhen; Chen, Ken-Chung; Li, Jianfu; Shen, Steve G. F.; Yan, Jin; Lee, Philip K. M.; Chow, Ben; Xia, James J.; Shen, Dinggang

2015-01-01

Purpose: A significant number of patients suffer from craniomaxillofacial (CMF) deformity and require CMF surgery in the United States. The success of CMF surgery depends on not only the surgical techniques but also an accurate surgical planning. However, surgical planning for CMF surgery is challenging due to the absence of a patient-specific reference model. Currently, the outcome of the surgery is often subjective and highly dependent on surgeon’s experience. In this paper, the authors present an automatic method to estimate an anatomically correct reference shape of jaws for orthognathic surgery, a common type of CMF surgery. Methods: To estimate a patient-specific jaw reference model, the authors use a data-driven method based on sparse shape composition. Given a dictionary of normal subjects, the authors first use the sparse representation to represent the midface of a patient by the midfaces of the normal subjects in the dictionary. Then, the derived sparse coefficients are used to reconstruct a patient-specific reference jaw shape. Results: The authors have validated the proposed method on both synthetic and real patient data. Experimental results show that the authors’ method can effectively reconstruct the normal shape of jaw for patients. Conclusions: The authors have presented a novel method to automatically estimate a patient-specific reference model for the patient suffering from CMF deformity. PMID:26429255

Comparison of in vitro flows past a mechanical heart valve in anatomical and axisymmetric aorta models

NASA Astrophysics Data System (ADS)

Haya, Laura; Tavoularis, Stavros

2017-06-01

Flow characteristics past a bileaflet mechanical heart valve were measured under physiological flow conditions in a straight tube with an axisymmetric expansion, similar to vessels used in previous studies, and in an anatomical model of the aorta. We found that anatomical features, including the three-lobed sinus and the aorta's curvature affected significantly the flow characteristics. The turbulent and viscous stresses were presented and discussed as indicators for potential blood damage and thrombosis. Both types of stresses, averaged over the two axial measurement planes, were significantly lower in the anatomical model than in the axisymmetric one. This difference was attributed to the lower height-to-width ratio and more gradual contraction of the anatomical aortic sinus. The curvature of the aorta caused asymmetries in the velocity and stress distributions during forward flow. Secondary flows resulting from the aorta's curvature are thought to have redistributed the fluid stresses transversely, resulting in a more homogeneous stress distribution in the anatomical aortic root than in the axisymmetric root. The results of this study demonstrate the importance of modelling accurately the aortic geometry in experimental and computational studies of prosthetic devices. Moreover, our findings suggest that grafts used for aortic root replacement should approximate as closely as possible the shape of the natural sinuses.

Soft Tissue Structure Modelling for Use in Orthopaedic Applications and Musculoskeletal Biomechanics

NASA Astrophysics Data System (ADS)

Audenaert, E. A.; Mahieu, P.; van Hoof, T.; Pattyn, C.

2009-12-01

We present our methodology for the three-dimensional anatomical and geometrical description of soft tissues, relevant for orthopaedic surgical applications and musculoskeletal biomechanics. The technique involves the segmentation and geometrical description of muscles and neurovascular structures from high-resolution computer tomography scanning for the reconstruction of generic anatomical models. These models can be used for quantitative interpretation of anatomical and biomechanical aspects of different soft tissue structures. This approach should allow the use of these data in other application fields, such as musculoskeletal modelling, simulations for radiation therapy, and databases for use in minimally invasive, navigated and robotic surgery.

Probabilistic Modeling and Visualization of the Flexibility in Morphable Models

NASA Astrophysics Data System (ADS)

Lüthi, M.; Albrecht, T.; Vetter, T.

Statistical shape models, and in particular morphable models, have gained widespread use in computer vision, computer graphics and medical imaging. Researchers have started to build models of almost any anatomical structure in the human body. While these models provide a useful prior for many image analysis task, relatively little information about the shape represented by the morphable model is exploited. We propose a method for computing and visualizing the remaining flexibility, when a part of the shape is fixed. Our method, which is based on Probabilistic PCA, not only leads to an approach for reconstructing the full shape from partial information, but also allows us to investigate and visualize the uncertainty of a reconstruction. To show the feasibility of our approach we performed experiments on a statistical model of the human face and the femur bone. The visualization of the remaining flexibility allows for greater insight into the statistical properties of the shape.

Bond Graph Model of Cerebral Circulation: Toward Clinically Feasible Systemic Blood Flow Simulations.

PubMed

Safaei, Soroush; Blanco, Pablo J; Müller, Lucas O; Hellevik, Leif R; Hunter, Peter J

2018-01-01

We propose a detailed CellML model of the human cerebral circulation that runs faster than real time on a desktop computer and is designed for use in clinical settings when the speed of response is important. A lumped parameter mathematical model, which is based on a one-dimensional formulation of the flow of an incompressible fluid in distensible vessels, is constructed using a bond graph formulation to ensure mass conservation and energy conservation. The model includes arterial vessels with geometric and anatomical data based on the ADAN circulation model. The peripheral beds are represented by lumped parameter compartments. We compare the hemodynamics predicted by the bond graph formulation of the cerebral circulation with that given by a classical one-dimensional Navier-Stokes model working on top of the whole-body ADAN model. Outputs from the bond graph model, including the pressure and flow signatures and blood volumes, are compared with physiological data.

Four-chamber heart modeling and automatic segmentation for 3-D cardiac CT volumes using marginal space learning and steerable features.

PubMed

Zheng, Yefeng; Barbu, Adrian; Georgescu, Bogdan; Scheuering, Michael; Comaniciu, Dorin

2008-11-01

We propose an automatic four-chamber heart segmentation system for the quantitative functional analysis of the heart from cardiac computed tomography (CT) volumes. Two topics are discussed: heart modeling and automatic model fitting to an unseen volume. Heart modeling is a nontrivial task since the heart is a complex nonrigid organ. The model must be anatomically accurate, allow manual editing, and provide sufficient information to guide automatic detection and segmentation. Unlike previous work, we explicitly represent important landmarks (such as the valves and the ventricular septum cusps) among the control points of the model. The control points can be detected reliably to guide the automatic model fitting process. Using this model, we develop an efficient and robust approach for automatic heart chamber segmentation in 3-D CT volumes. We formulate the segmentation as a two-step learning problem: anatomical structure localization and boundary delineation. In both steps, we exploit the recent advances in learning discriminative models. A novel algorithm, marginal space learning (MSL), is introduced to solve the 9-D similarity transformation search problem for localizing the heart chambers. After determining the pose of the heart chambers, we estimate the 3-D shape through learning-based boundary delineation. The proposed method has been extensively tested on the largest dataset (with 323 volumes from 137 patients) ever reported in the literature. To the best of our knowledge, our system is the fastest with a speed of 4.0 s per volume (on a dual-core 3.2-GHz processor) for the automatic segmentation of all four chambers.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lian, Jun, E-mail: jun-lian@med.unc.edu; Chera, Bhishamjit S.; Chang, Sha

Purpose: To build a statistical model to quantitatively correlate the anatomic features of structures and the corresponding dose-volume histogram (DVH) of head and neck (HN) Tomotherapy (Tomo) plans. To study if the model built upon one intensity modulated radiation therapy (IMRT) technique (such as conventional Linac) can be used to predict anticipated organs-at-risk (OAR) DVH of patients treated with a different IMRT technique (such as Tomo). To study if the model built upon the clinical experience of one institution can be used to aid IMRT planning for another institution. Methods: Forty-four Tomotherapy intensity modulate radiotherapy plans of HN cases (Tomo-IMRT)more » from Institution A were included in the study. A different patient group of 53 HN fixed gantry IMRT (FG-IMRT) plans was selected from Institution B. The analyzed OARs included the parotid, larynx, spinal cord, brainstem, and submandibular gland. Two major groups of anatomical features were considered: the volumetric information and the spatial information. The volume information includes the volume of target, OAR, and overlapped volume between target and OAR. The spatial information of OARs relative to PTVs was represented by the distance-to-target histogram (DTH). Important anatomical and dosimetric features were extracted from DTH and DVH by principal component analysis. Two regression models, one for Tomotherapy plan and one for IMRT plan, were built independently. The accuracy of intratreatment-modality model prediction was validated by a leave one out cross-validation method. The intertechnique and interinstitution validations were performed by using the FG-IMRT model to predict the OAR dosimetry of Tomo-IMRT plans. The dosimetry of OARs, under the same and different institutional preferences, was analyzed to examine the correlation between the model prediction and planning protocol. Results: Significant patient anatomical factors contributing to OAR dose sparing in HN Tomotherapy plans have been analyzed and identified. For all the OARs, the discrepancies of dose indices between the model predicted values and the actual plan values were within 2.1%. Similar results were obtained from the modeling of FG-IMRT plans. The parotid gland was spared in a comparable fashion during the treatment planning of two institutions. The model based on FG-IMRT plans was found to predict the median dose of the parotid of Tomotherapy plans quite well, with a mean error of 2.6%. Predictions from the FG-IMRT model suggested the median dose of the larynx, median dose of the brainstem and D2 of the brainstem could be reduced by 10.5%, 12.8%, and 20.4%, respectively, in the Tomo-IMRT plans. This was found to be correlated to the institutional differences in OAR constraint settings. Re-planning of six Tomotherapy patients confirmed the potential of optimization improvement predicted by the FG-IMRT model was correct. Conclusions: The authors established a mathematical model to correlate the anatomical features and dosimetric indexes of OARs of HN patients in Tomotherapy plans. The model can be used for the setup of patient-specific OAR dose sparing goals and quality control of planning results. The institutional clinical experience was incorporated into the model which allows the model from one institution to generate a reference plan for another institution, or another IMRT technique.« less

Anatomical location of metastatic lymph nodes: an indispensable prognostic factor for gastric cancer patients who underwent curative resection.

PubMed

Zhao, Bochao; Zhang, Jingting; Zhang, Jiale; Chen, Xiuxiu; Chen, Junqing; Wang, Zhenning; Xu, Huimian; Huang, Baojun

2018-02-01

Although the numeric-based lymph node (LN) staging was widely used in the worldwide, it did not represent the anatomical location of metastatic lymph nodes (MLNs) and not reflect extent of LN dissection. Therefore, in the present study, we investigated whether the anatomical location of MLNs was still necessary to evaluate the prognosis of node-positive gastric cancer (GC) patients. We reviewed 1451 GC patients who underwent radical gastrectomy in our institution between January 1986 and January 2008. All patients were reclassified into several groups according to the anatomical location of MLNs and the number of MLNs. The prognostic differences between different patient groups were compared and clinicopathologic features were analyzed. In the present study, both anatomical location of MLNs and the number of MLNs were identified as the independent prognostic factors (p < .01). The patients with extraperigastric LN involvement showed a poorer prognosis compared with the perigastric-only group (p < .001). For the N1-N2 stage patients, the prognostic discrepancy was still observed among them when the anatomical location of MLNs was considered (p < .05). For the N3-stage patients, although the anatomical location of MLNs had no significant effect on the prognosis of these patients, the higher number of MLNs in the extraperigastric area was correlated with the unfavorable prognosis (p < .05). The anatomical location of MLNs was an important factor influencing the prognostic outcome of GC patients. To provide more accurate prognostic information for GC patients, the anatomical location of MLNs should not be ignored.

Network diffusion accurately models the relationship between structural and functional brain connectivity networks

PubMed Central

Abdelnour, Farras; Voss, Henning U.; Raj, Ashish

2014-01-01

The relationship between anatomic connectivity of large-scale brain networks and their functional connectivity is of immense importance and an area of active research. Previous attempts have required complex simulations which model the dynamics of each cortical region, and explore the coupling between regions as derived by anatomic connections. While much insight is gained from these non-linear simulations, they can be computationally taxing tools for predicting functional from anatomic connectivities. Little attention has been paid to linear models. Here we show that a properly designed linear model appears to be superior to previous non-linear approaches in capturing the brain’s long-range second order correlation structure that governs the relationship between anatomic and functional connectivities. We derive a linear network of brain dynamics based on graph diffusion, whereby the diffusing quantity undergoes a random walk on a graph. We test our model using subjects who underwent diffusion MRI and resting state fMRI. The network diffusion model applied to the structural networks largely predicts the correlation structures derived from their fMRI data, to a greater extent than other approaches. The utility of the proposed approach is that it can routinely be used to infer functional correlation from anatomic connectivity. And since it is linear, anatomic connectivity can also be inferred from functional data. The success of our model confirms the linearity of ensemble average signals in the brain, and implies that their long-range correlation structure may percolate within the brain via purely mechanistic processes enacted on its structural connectivity pathways. PMID:24384152

Design, development and clinical validation of computer-aided surgical simulation system for streamlined orthognathic surgical planning.

PubMed

Yuan, Peng; Mai, Huaming; Li, Jianfu; Ho, Dennis Chun-Yu; Lai, Yingying; Liu, Siting; Kim, Daeseung; Xiong, Zixiang; Alfi, David M; Teichgraeber, John F; Gateno, Jaime; Xia, James J

2017-12-01

There are many proven problems associated with traditional surgical planning methods for orthognathic surgery. To address these problems, we developed a computer-aided surgical simulation (CASS) system, the AnatomicAligner, to plan orthognathic surgery following our streamlined clinical protocol. The system includes six modules: image segmentation and three-dimensional (3D) reconstruction, registration and reorientation of models to neutral head posture, 3D cephalometric analysis, virtual osteotomy, surgical simulation, and surgical splint generation. The accuracy of the system was validated in a stepwise fashion: first to evaluate the accuracy of AnatomicAligner using 30 sets of patient data, then to evaluate the fitting of splints generated by AnatomicAligner using 10 sets of patient data. The industrial gold standard system, Mimics, was used as the reference. When comparing the results of segmentation, virtual osteotomy and transformation achieved with AnatomicAligner to the ones achieved with Mimics, the absolute deviation between the two systems was clinically insignificant. The average surface deviation between the two models after 3D model reconstruction in AnatomicAligner and Mimics was 0.3 mm with a standard deviation (SD) of 0.03 mm. All the average surface deviations between the two models after virtual osteotomy and transformations were smaller than 0.01 mm with a SD of 0.01 mm. In addition, the fitting of splints generated by AnatomicAligner was at least as good as the ones generated by Mimics. We successfully developed a CASS system, the AnatomicAligner, for planning orthognathic surgery following the streamlined planning protocol. The system has been proven accurate. AnatomicAligner will soon be available freely to the boarder clinical and research communities.

Design, development and clinical validation of computer-aided surgical simulation system for streamlined orthognathic surgical planning

PubMed Central

Yuan, Peng; Mai, Huaming; Li, Jianfu; Ho, Dennis Chun-Yu; Lai, Yingying; Liu, Siting; Kim, Daeseung; Xiong, Zixiang; Alfi, David M.; Teichgraeber, John F.; Gateno, Jaime

2017-01-01

Purpose There are many proven problems associated with traditional surgical planning methods for orthognathic surgery. To address these problems, we developed a computer-aided surgical simulation (CASS) system, the AnatomicAligner, to plan orthognathic surgery following our streamlined clinical protocol. Methods The system includes six modules: image segmentation and three-dimensional (3D) reconstruction, registration and reorientation of models to neutral head posture, 3D cephalometric analysis, virtual osteotomy, surgical simulation, and surgical splint generation. The accuracy of the system was validated in a stepwise fashion: first to evaluate the accuracy of AnatomicAligner using 30 sets of patient data, then to evaluate the fitting of splints generated by AnatomicAligner using 10 sets of patient data. The industrial gold standard system, Mimics, was used as the reference. Result When comparing the results of segmentation, virtual osteotomy and transformation achieved with AnatomicAligner to the ones achieved with Mimics, the absolute deviation between the two systems was clinically insignificant. The average surface deviation between the two models after 3D model reconstruction in AnatomicAligner and Mimics was 0.3 mm with a standard deviation (SD) of 0.03 mm. All the average surface deviations between the two models after virtual osteotomy and transformations were smaller than 0.01 mm with a SD of 0.01 mm. In addition, the fitting of splints generated by AnatomicAligner was at least as good as the ones generated by Mimics. Conclusion We successfully developed a CASS system, the AnatomicAligner, for planning orthognathic surgery following the streamlined planning protocol. The system has been proven accurate. AnatomicAligner will soon be available freely to the boarder clinical and research communities. PMID:28432489

Toward knowledge-enhanced viewing using encyclopedias and model-based segmentation

NASA Astrophysics Data System (ADS)

Kneser, Reinhard; Lehmann, Helko; Geller, Dieter; Qian, Yue-Chen; Weese, Jürgen

2009-02-01

To make accurate decisions based on imaging data, radiologists must associate the viewed imaging data with the corresponding anatomical structures. Furthermore, given a disease hypothesis possible image findings which verify the hypothesis must be considered and where and how they are expressed in the viewed images. If rare anatomical variants, rare pathologies, unfamiliar protocols, or ambiguous findings are present, external knowledge sources such as medical encyclopedias are consulted. These sources are accessed using keywords typically describing anatomical structures, image findings, pathologies. In this paper we present our vision of how a patient's imaging data can be automatically enhanced with anatomical knowledge as well as knowledge about image findings. On one hand, we propose the automatic annotation of the images with labels from a standard anatomical ontology. These labels are used as keywords for a medical encyclopedia such as STATdx to access anatomical descriptions, information about pathologies and image findings. On the other hand we envision encyclopedias to contain links to region- and finding-specific image processing algorithms. Then a finding is evaluated on an image by applying the respective algorithm in the associated anatomical region. Towards realization of our vision, we present our method and results of automatic annotation of anatomical structures in 3D MRI brain images. Thereby we develop a complex surface mesh model incorporating major structures of the brain and a model-based segmentation method. We demonstrate the validity by analyzing the results of several training and segmentation experiments with clinical data focusing particularly on the visual pathway.

3D printing the pterygopalatine fossa: a negative space model of a complex structure.

PubMed

Bannon, Ross; Parihar, Shivani; Skarparis, Yiannis; Varsou, Ourania; Cezayirli, Enis

2018-02-01

The pterygopalatine fossa is one of the most complex anatomical regions to understand. It is poorly visualized in cadaveric dissection and most textbooks rely on schematic depictions. We describe our approach to creating a low-cost, 3D model of the pterygopalatine fossa, including its associated canals and foramina, using an affordable "desktop" 3D printer. We used open source software to create a volume render of the pterygopalatine fossa from axial slices of a head computerised tomography scan. These data were then exported to a 3D printer to produce an anatomically accurate model. The resulting 'negative space' model of the pterygopalatine fossa provides a useful and innovative aid for understanding the complex anatomical relationships of the pterygopalatine fossa. This model was designed primarily for medical students; however, it will also be of interest to postgraduates in ENT, ophthalmology, neurosurgery, and radiology. The technical process described may be replicated by other departments wishing to develop their own anatomical models whilst incurring minimal costs.

STATISTICAL GROWTH MODELING OF LONGITUDINAL DT-MRI FOR REGIONAL CHARACTERIZATION OF EARLY BRAIN DEVELOPMENT.

PubMed

Sadeghi, Neda; Prastawa, Marcel; Fletcher, P Thomas; Gilmore, John H; Lin, Weili; Gerig, Guido

2012-01-01

A population growth model that represents the growth trajectories of individual subjects is critical to study and understand neurodevelopment. This paper presents a framework for jointly estimating and modeling individual and population growth trajectories, and determining significant regional differences in growth pattern characteristics applied to longitudinal neuroimaging data. We use non-linear mixed effect modeling where temporal change is modeled by the Gompertz function. The Gompertz function uses intuitive parameters related to delay, rate of change, and expected asymptotic value; all descriptive measures which can answer clinical questions related to growth. Our proposed framework combines nonlinear modeling of individual trajectories, population analysis, and testing for regional differences. We apply this framework to the study of early maturation in white matter regions as measured with diffusion tensor imaging (DTI). Regional differences between anatomical regions of interest that are known to mature differently are analyzed and quantified. Experiments with image data from a large ongoing clinical study show that our framework provides descriptive, quantitative information on growth trajectories that can be directly interpreted by clinicians. To our knowledge, this is the first longitudinal analysis of growth functions to explain the trajectory of early brain maturation as it is represented in DTI.

Scaling of Topologically Similar Functional Modules Defines Mouse Primary Auditory and Somatosensory Microcircuitry

PubMed Central

Sadovsky, Alexander J.

2013-01-01

Mapping the flow of activity through neocortical microcircuits provides key insights into the underlying circuit architecture. Using a comparative analysis we determined the extent to which the dynamics of microcircuits in mouse primary somatosensory barrel field (S1BF) and auditory (A1) neocortex generalize. We imaged the simultaneous dynamics of up to 1126 neurons spanning multiple columns and layers using high-speed multiphoton imaging. The temporal progression and reliability of reactivation of circuit events in both regions suggested common underlying cortical design features. We used circuit activity flow to generate functional connectivity maps, or graphs, to test the microcircuit hypothesis within a functional framework. S1BF and A1 present a useful test of the postulate as both regions map sensory input anatomically, but each area appears organized according to different design principles. We projected the functional topologies into anatomical space and found benchmarks of organization that had been previously described using physiology and anatomical methods, consistent with a close mapping between anatomy and functional dynamics. By comparing graphs representing activity flow we found that each region is similarly organized as highlighted by hallmarks of small world, scale free, and hierarchical modular topologies. Models of prototypical functional circuits from each area of cortex were sufficient to recapitulate experimentally observed circuit activity. Convergence to common behavior by these models was accomplished using preferential attachment to scale from an auditory up to a somatosensory circuit. These functional data imply that the microcircuit hypothesis be framed as scalable principles of neocortical circuit design. PMID:23986241

Validation of model-based deformation correction in image-guided liver surgery via tracked intraoperative ultrasound: preliminary method and results

NASA Astrophysics Data System (ADS)

Clements, Logan W.; Collins, Jarrod A.; Wu, Yifei; Simpson, Amber L.; Jarnagin, William R.; Miga, Michael I.

2015-03-01

Soft tissue deformation represents a significant error source in current surgical navigation systems used for open hepatic procedures. While numerous algorithms have been proposed to rectify the tissue deformation that is encountered during open liver surgery, clinical validation of the proposed methods has been limited to surface based metrics and sub-surface validation has largely been performed via phantom experiments. Tracked intraoperative ultrasound (iUS) provides a means to digitize sub-surface anatomical landmarks during clinical procedures. The proposed method involves the validation of a deformation correction algorithm for open hepatic image-guided surgery systems via sub-surface targets digitized with tracked iUS. Intraoperative surface digitizations were acquired via a laser range scanner and an optically tracked stylus for the purposes of computing the physical-to-image space registration within the guidance system and for use in retrospective deformation correction. Upon completion of surface digitization, the organ was interrogated with a tracked iUS transducer where the iUS images and corresponding tracked locations were recorded. After the procedure, the clinician reviewed the iUS images to delineate contours of anatomical target features for use in the validation procedure. Mean closest point distances between the feature contours delineated in the iUS images and corresponding 3-D anatomical model generated from the preoperative tomograms were computed to quantify the extent to which the deformation correction algorithm improved registration accuracy. The preliminary results for two patients indicate that the deformation correction method resulted in a reduction in target error of approximately 50%.

ASTM F1717 standard for the preclinical evaluation of posterior spinal fixators: can we improve it?

PubMed

La Barbera, Luigi; Galbusera, Fabio; Villa, Tomaso; Costa, Francesco; Wilke, Hans-Joachim

2014-10-01

Preclinical evaluation of spinal implants is a necessary step to ensure their reliability and safety before implantation. The American Society for Testing and Materials reapproved F1717 standard for the assessment of mechanical properties of posterior spinal fixators, which simulates a vertebrectomy model and recommends mimicking vertebral bodies using polyethylene blocks. This set-up should represent the clinical use, but available data in the literature are few. Anatomical parameters depending on the spinal level were compared to published data or measurements on biplanar stereoradiography on 13 patients. Other mechanical variables, describing implant design were considered, and all parameters were investigated using a numerical parametric finite element model. Stress values were calculated by considering either the combination of the average values for each parameter or their worst-case combination depending on the spinal level. The standard set-up represents quite well the anatomy of an instrumented average thoracolumbar segment. The stress on the pedicular screw is significantly influenced by the lever arm of the applied load, the unsupported screw length, the position of the centre of rotation of the functional spine unit and the pedicular inclination with respect to the sagittal plane. The worst-case combination of parameters demonstrates that devices implanted below T5 could potentially undergo higher stresses than those described in the standard suggestions (maximum increase of 22.2% at L1). We propose to revise F1717 in order to describe the anatomical worst case condition we found at L1 level: this will guarantee higher safety of the implant for a wider population of patients. © IMechE 2014.

Aerobic power and flight capacity in birds: a phylogenetic test of the heart-size hypothesis.

PubMed

Nespolo, Roberto F; González-Lagos, César; Solano-Iguaran, Jaiber J; Elfwing, Magnus; Garitano-Zavala, Alvaro; Mañosa, Santiago; Alonso, Juan Carlos; Altimiras, Jordi

2018-01-09

Flight capacity is one of the most important innovations in animal evolution; it only evolved in insects, birds, mammals and the extinct pterodactyls. Given that powered flight represents a demanding aerobic activity, an efficient cardiovascular system is essential for the continuous delivery of oxygen to the pectoral muscles during flight. It is well known that the limiting step in the circulation is stroke volume (the volume of blood pumped from the ventricle to the body during each beat), which is determined by the size of the ventricle. Thus, the fresh mass of the heart represents a simple and repeatable anatomical measure of the aerobic power of an animal. Although several authors have compared heart masses across bird species, a phylogenetic comparative analysis is still lacking. By compiling heart sizes for 915 species and applying several statistical procedures controlling for body size and/or testing for adaptive trends in the dataset (e.g. model selection approaches, phylogenetic generalized linear models), we found that (residuals of) heart size is consistently associated with four categories of flight capacity. In general, our results indicate that species exhibiting continuous hovering flight (i.e. hummingbirds) have substantially larger hearts than other groups, species that use flapping flight and gliding show intermediate values, and that species categorized as poor flyers show the smallest values. Our study reveals that on a broad scale, routine flight modes seem to have shaped the energetic requirements of birds sufficiently to be anatomically detected at the comparative level. © 2018. Published by The Company of Biologists Ltd.

In Vivo Bone Formation Within Engineered Hydroxyapatite Scaffolds in a Sheep Model.

PubMed

Lovati, A B; Lopa, S; Recordati, C; Talò, G; Turrisi, C; Bottagisio, M; Losa, M; Scanziani, E; Moretti, M

2016-08-01

Large bone defects still represent a major burden in orthopedics, requiring bone-graft implantation to promote the bone repair. Along with autografts that currently represent the gold standard for complicated fracture repair, the bone tissue engineering offers a promising alternative strategy combining bone-graft substitutes with osteoprogenitor cells able to support the bone tissue ingrowth within the implant. Hence, the optimization of cell loading and distribution within osteoconductive scaffolds is mandatory to support a successful bone formation within the scaffold pores. With this purpose, we engineered constructs by seeding and culturing autologous, osteodifferentiated bone marrow mesenchymal stem cells within hydroxyapatite (HA)-based grafts by means of a perfusion bioreactor to enhance the in vivo implant-bone osseointegration in an ovine model. Specifically, we compared the engineered constructs in two different anatomical bone sites, tibia, and femur, compared with cell-free or static cell-loaded scaffolds. After 2 and 4 months, the bone formation and the scaffold osseointegration were assessed by micro-CT and histological analyses. The results demonstrated the capability of the acellular HA-based grafts to determine an implant-bone osseointegration similar to that of statically or dynamically cultured grafts. Our study demonstrated that the tibia is characterized by a lower bone repair capability compared to femur, in which the contribution of transplanted cells is not crucial to enhance the bone-implant osseointegration. Indeed, only in tibia, the dynamic cell-loaded implants performed slightly better than the cell-free or static cell-loaded grafts, indicating that this is a valid approach to sustain the bone deposition and osseointegration in disadvantaged anatomical sites.

Work domain constraints for modelling surgical performance.

PubMed

Morineau, Thierry; Riffaud, Laurent; Morandi, Xavier; Villain, Jonathan; Jannin, Pierre

2015-10-01

Three main approaches can be identified for modelling surgical performance: a competency-based approach, a task-based approach, both largely explored in the literature, and a less known work domain-based approach. The work domain-based approach first describes the work domain properties that constrain the agent's actions and shape the performance. This paper presents a work domain-based approach for modelling performance during cervical spine surgery, based on the idea that anatomical structures delineate the surgical performance. This model was evaluated through an analysis of junior and senior surgeons' actions. Twenty-four cervical spine surgeries performed by two junior and two senior surgeons were recorded in real time by an expert surgeon. According to a work domain-based model describing an optimal progression through anatomical structures, the degree of adjustment of each surgical procedure to a statistical polynomial function was assessed. Each surgical procedure showed a significant suitability with the model and regression coefficient values around 0.9. However, the surgeries performed by senior surgeons fitted this model significantly better than those performed by junior surgeons. Analysis of the relative frequencies of actions on anatomical structures showed that some specific anatomical structures discriminate senior from junior performances. The work domain-based modelling approach can provide an overall statistical indicator of surgical performance, but in particular, it can highlight specific points of interest among anatomical structures that the surgeons dwelled on according to their level of expertise.

Computational model of soft tissues in the human upper airway.

PubMed

Pelteret, J-P V; Reddy, B D

2012-01-01

This paper presents a three-dimensional finite element model of the tongue and surrounding soft tissues with potential application to the study of sleep apnoea and of linguistics and speech therapy. The anatomical data was obtained from the Visible Human Project, and the underlying histological data was also extracted and incorporated into the model. Hyperelastic constitutive models were used to describe the material behaviour, and material incompressibility was accounted for. An active Hill three-element muscle model was used to represent the muscular tissue of the tongue. The neural stimulus for each muscle group was determined through the use of a genetic algorithm-based neural control model. The fundamental behaviour of the tongue under gravitational and breathing-induced loading is investigated. It is demonstrated that, when a time-dependent loading is applied to the tongue, the neural model is able to control the position of the tongue and produce a physiologically realistic response for the genioglossus.

The potential for machine learning algorithms to improve and reduce the cost of 3-dimensional printing for surgical planning.

PubMed

Huff, Trevor J; Ludwig, Parker E; Zuniga, Jorge M

2018-05-01

3D-printed anatomical models play an important role in medical and research settings. The recent successes of 3D anatomical models in healthcare have led many institutions to adopt the technology. However, there remain several issues that must be addressed before it can become more wide-spread. Of importance are the problems of cost and time of manufacturing. Machine learning (ML) could be utilized to solve these issues by streamlining the 3D modeling process through rapid medical image segmentation and improved patient selection and image acquisition. The current challenges, potential solutions, and future directions for ML and 3D anatomical modeling in healthcare are discussed. Areas covered: This review covers research articles in the field of machine learning as related to 3D anatomical modeling. Topics discussed include automated image segmentation, cost reduction, and related time constraints. Expert commentary: ML-based segmentation of medical images could potentially improve the process of 3D anatomical modeling. However, until more research is done to validate these technologies in clinical practice, their impact on patient outcomes will remain unknown. We have the necessary computational tools to tackle the problems discussed. The difficulty now lies in our ability to collect sufficient data.

The United States Air Force and the Culture of Innovation, 1945-1965

DTIC Science & Technology

2002-01-01

US Dept of Transportation; typically they hover between 85 and 95 percent. 16. Kent C. Redmond and Thomas M. Smith, Project Whirlwind: A Case Histo...Washing- ton, D.C.: AF Hist and Museums Prog, 1994). 14. Thomas A . Sturm, The USAF SAB: Its First Twenty Years 1944–1964 (Washington, D.C.: USAF...allegations at Ramo-Wooldridge and the Air Force’s approach. Schriever answered them in a letter to Lt. Gen. Thomas Power, the commander of ARDC, in

Analytical and Radio-Histo-Chemical Experiments of Plants and Tissue Culture Cells Treated with Lunar and Terrestrial Materials

NASA Technical Reports Server (NTRS)

Halliwell, R. S.

1973-01-01

The nature and mechanisms of the apparent simulation of growth originally observed in plants growing in contact with lunar soil during the Apollo project quarantine are examined. Preliminary experiments employing neutron activated lunar soil indicate uptake of a few elements by plants. It was found that while the preliminary neutron activation technique allowed demonstration of uptake of minerals it presented numerous disadvantages for use in critical experiments directed at elucidating possible mechanisms of stimulation.

Light Armor Plate Development

DTIC Science & Technology

1923-07-28

to thie time ot shipment will be ini- eluded, 06otioIjAs -- HistoT. On Dec ember 2S# lt~. uVeity -four plates -*ere raaivad fro* Watertown Are nal, Th...only AT .Jwi-ace Vvrl/ac e 914yramof specl .mens elsed for h7eat- treatment 12aiomArmor- P/ate Anyepstyatio,, Vi -oorner o! ogoii uipe’Aven va...tempering temperatures applied. Only oarburized specimens were suboted to the double- quenching treatment (see table IV). The purpose of this Waq to

International Conference on Crystal Growth (10th) Held in San Diego, California, on 16-21 August 1992

DTIC Science & Technology

1993-07-14

precipitation. This additive appeared to retard growth be different for the nuclei formed on additive molecules and and to stimulate nucleation of BaSO4...dispersion is described by some of different crystals of the same material grow at different rates. the mentioned distributions. Aiming at that, the...of crystals that grow with different a from the histo- grams of distributions of crystal growth rates [2,3], and it is 1. U.K. Burton et al., Phil

Preliminary Study on Appearance-Based Detection of Anatomical Point Landmarks in Body Trunk CT Images

NASA Astrophysics Data System (ADS)

Nemoto, Mitsutaka; Nomura, Yukihiro; Hanaoka, Shohei; Masutani, Yoshitaka; Yoshikawa, Takeharu; Hayashi, Naoto; Yoshioka, Naoki; Ohtomo, Kuni

Anatomical point landmarks as most primitive anatomical knowledge are useful for medical image understanding. In this study, we propose a detection method for anatomical point landmark based on appearance models, which include gray-level statistical variations at point landmarks and their surrounding area. The models are built based on results of Principal Component Analysis (PCA) of sample data sets. In addition, we employed generative learning method by transforming ROI of sample data. In this study, we evaluated our method with 24 data sets of body trunk CT images and obtained 95.8 ± 7.3 % of the average sensitivity in 28 landmarks.

A new training model for robot-assisted urethrovesical anastomosis and posterior muscle-fascial reconstruction: the Verona training technique.

PubMed

Cacciamani, G; De Marco, V; Siracusano, S; De Marchi, D; Bizzotto, L; Cerruto, M A; Motton, G; Porcaro, A B; Artibani, W

2017-06-01

A training model is usually needed to teach robotic surgical technique successfully. In this way, an ideal training model should mimic as much as possible the "in vivo" procedure and allow several consecutive surgical simulations. The goal of this study was to create a "wet lab" model suitable for RARP training programs, providing the simulation of the posterior fascial reconstruction. The second aim was to compare the original "Venezuelan" chicken model described by Sotelo to our training model. Our training model consists of performing an anastomosis, reproducing the surgical procedure in "vivo" as in RARP, between proventriculus and the proximal portion of the esophagus. A posterior fascial reconstruction simulating Rocco's stitch is performed between the tissues located under the posterior surface of the esophagus and the tissue represented by the serosa of the proventriculus. From 2014 to 2015, during 6 different full-immersion training courses, thirty-four surgeons performed the urethrovesical anastomosis using our model and the Sotelo's one. After the training period, each surgeon was asked to fill out a non-validated questionnaire to perform an evaluation of the differences between the two training models. Our model was judged the best model, in terms of similarity with urethral tissue and similarity with the anatomic unit urethra-pelvic wall. Our training model as reported by all trainees is easily reproducible and anatomically comparable with the urethrovesical anastomosis as performed during radical prostatectomy in humans. It is suitable for performing posterior fascial reconstruction reported by Rocco. In this context, our surgical training model could be routinely proposed in all robotic training courses to develop specific expertise in urethrovesical anastomosis with the reproducibility of the Rocco stitch.

A probabilistic framework to infer brain functional connectivity from anatomical connections.

PubMed

Deligianni, Fani; Varoquaux, Gael; Thirion, Bertrand; Robinson, Emma; Sharp, David J; Edwards, A David; Rueckert, Daniel

2011-01-01

We present a novel probabilistic framework to learn across several subjects a mapping from brain anatomical connectivity to functional connectivity, i.e. the covariance structure of brain activity. This prediction problem must be formulated as a structured-output learning task, as the predicted parameters are strongly correlated. We introduce a model selection framework based on cross-validation with a parametrization-independent loss function suitable to the manifold of covariance matrices. Our model is based on constraining the conditional independence structure of functional activity by the anatomical connectivity. Subsequently, we learn a linear predictor of a stationary multivariate autoregressive model. This natural parameterization of functional connectivity also enforces the positive-definiteness of the predicted covariance and thus matches the structure of the output space. Our results show that functional connectivity can be explained by anatomical connectivity on a rigorous statistical basis, and that a proper model of functional connectivity is essential to assess this link.

Development of anatomically and dielectrically accurate breast phantoms for microwave imaging applications

NASA Astrophysics Data System (ADS)

O'Halloran, M.; Lohfeld, S.; Ruvio, G.; Browne, J.; Krewer, F.; Ribeiro, C. O.; Inacio Pita, V. C.; Conceicao, R. C.; Jones, E.; Glavin, M.

2014-05-01

Breast cancer is one of the most common cancers in women. In the United States alone, it accounts for 31% of new cancer cases, and is second only to lung cancer as the leading cause of deaths in American women. More than 184,000 new cases of breast cancer are diagnosed each year resulting in approximately 41,000 deaths. Early detection and intervention is one of the most significant factors in improving the survival rates and quality of life experienced by breast cancer sufferers, since this is the time when treatment is most effective. One of the most promising breast imaging modalities is microwave imaging. The physical basis of active microwave imaging is the dielectric contrast between normal and malignant breast tissue that exists at microwave frequencies. The dielectric contrast is mainly due to the increased water content present in the cancerous tissue. Microwave imaging is non-ionizing, does not require breast compression, is less invasive than X-ray mammography, and is potentially low cost. While several prototype microwave breast imaging systems are currently in various stages of development, the design and fabrication of anatomically and dielectrically representative breast phantoms to evaluate these systems is often problematic. While some existing phantoms are composed of dielectrically representative materials, they rarely accurately represent the shape and size of a typical breast. Conversely, several phantoms have been developed to accurately model the shape of the human breast, but have inappropriate dielectric properties. This study will brie y review existing phantoms before describing the development of a more accurate and practical breast phantom for the evaluation of microwave breast imaging systems.

A pilot study on objective quantification and anatomical modelling of in vivo head and neck positions commonly applied in training and competition of sport horses.

PubMed

Elgersma, A E; Wijnberg, I D; Sleutjens, J; van der Kolk, J H; van Weeren, P R; Back, W

2010-11-01

Head and neck positions (HNP) in sport horses are under debate in the equine community, as they could interfere with equine welfare. HNPs have not been quantified objectively and no information is available on their head and neck loading. To quantify in vivo HNPs in sport horses and develop o a model to estimate loading on the cervical vertebrae in these positions. Videos were taken of 7 Warmbloods at walk on a straight line in 5 positions, representing all HNPs during Warmblood training and competition. Markers were glued at 5 anatomical landmarks. Two-dimensional angles and distances were determined from video frames for the 5 HNPs and statistically compared (P < 0.05). A new simulation model was developed to estimate nuchal ligament cervical loading at these HNPs. The mean angles were significantly different between the 5 HNPs for the line between C1 and T6 with the horizontal and for the line connecting the facial crest (CF) and C1 with the vertical, while the vertical distance from CF to the lateral styloid process of the radius (PS) was significantly different between all 5 positions (P < 0.05). The estimated nuchal ligament loading appeared to be largest at the origin of C2 for all HNPs, except for the 'hyperextended' HNP5; the 'hyperflexed' HNP4 showed the largest loading values on the nuchal ligament origins at all locations. HNPs can be accurately quantified in the sagittal plane from angles and distances based on standard anatomical landmarks and home-video captured images. Nuchal ligament loading showed the largest estimated values at its origin on C2 in hyperflexion (HNP4). Modelling opens further perspectives to eventually estimate loading for individual horses and thus ergonomically optimise their HNP, which may improve the welfare of the sport horse during training and competition. © 2010 EVJ Ltd.

Three-dimensional representation of the human cochlea using micro-computed tomography data: presenting an anatomical model for further numerical calculations.

PubMed

Braun, Katharina; Böhnke, Frank; Stark, Thomas

2012-06-01

We present a complete geometric model of the human cochlea, including the segmentation and reconstruction of the fluid-filled chambers scala tympani and scala vestibuli, the lamina spiralis ossea and the vibrating structure (cochlear partition). Future fluid-structure coupled simulations require a reliable geometric model of the cochlea. The aim of this study was to present an anatomical model of the human cochlea, which can be used for further numerical calculations. Using high resolution micro-computed tomography (µCT), we obtained images of a cut human temporal bone with a spatial resolution of 5.9 µm. Images were manually segmented to obtain the three-dimensional reconstruction of the cochlea. Due to the high resolution of the µCT data, a detailed examination of the geometry of the twisted cochlear partition near the oval and the round window as well as the precise illustration of the helicotrema was possible. After reconstruction of the lamina spiralis ossea, the cochlear partition and the curved geometry of the scala vestibuli and the scala tympani were presented. The obtained data sets were exported as standard lithography (stl) files. These files represented a complete framework for future numerical simulations of mechanical (acoustic) wave propagation on the cochlear partition in the form of mathematical mechanical cochlea models. Additional quantitative information concerning heights, lengths and volumes of the scalae was found and compared with previous results.

A functional-anatomical approach to the spine-pelvis mechanism: interaction between the biceps femoris muscle and the sacrotuberous ligament.

PubMed

van Wingerden, J P; Vleeming, A; Snijders, C J; Stoeckart, R

1993-10-01

Summary. Sacroiliac joint dysfunction is often overlooked as a possible cause of low back pain. This is due to the use of reductionistic anatomical models. From a kinematic point of view, topographic anatomical models are generally inadequate since they categorize pelvis, lower vertebral column and legs as distinct entities. This functional-anatomical study focuses on the question whether anatomical connections between the biceps femoris muscle and the sacrotuberous ligament are kinematically useful. Forces applied to the tendon of the biceps femoris muscle, simulating biceps femoris muscle force, were shown to influence sacrotuberous ligament tension. Since sacrotuberous ligament tension influences sacroiliac joint kinematics, hamstring training could influence the sacroiliac joint and thus low back kinematics. The clinical implications with respect to 'short' hamstrings, pelvic instability and walking are discussed.

Material Models and Properties in the Finite Element Analysis of Knee Ligaments: A Literature Review

PubMed Central

Galbusera, Fabio; Freutel, Maren; Dürselen, Lutz; D’Aiuto, Marta; Croce, Davide; Villa, Tomaso; Sansone, Valerio; Innocenti, Bernardo

2014-01-01

Knee ligaments are elastic bands of soft tissue with a complex microstructure and biomechanics, which are critical to determine the kinematics as well as the stress bearing behavior of the knee joint. Their correct implementation in terms of material models and properties is therefore necessary in the development of finite element models of the knee, which has been performed for decades for the investigation of both its basic biomechanics and the development of replacement implants and repair strategies for degenerative and traumatic pathologies. Indeed, a wide range of element types and material models has been used to represent knee ligaments, ranging from elastic unidimensional elements to complex hyperelastic three-dimensional structures with anatomically realistic shapes. This paper systematically reviews literature studies, which described finite element models of the knee, and summarizes the approaches, which have been used to model the ligaments highlighting their strengths and weaknesses. PMID:25478560

TNM-O: ontology support for staging of malignant tumours.

PubMed

Boeker, Martin; França, Fábio; Bronsert, Peter; Schulz, Stefan

2016-11-14

Objectives of this work are to (1) present an ontological framework for the TNM classification system, (2) exemplify this framework by an ontology for colon and rectum tumours, and (3) evaluate this ontology by assigning TNM classes to real world pathology data. The TNM ontology uses the Foundational Model of Anatomy for anatomical entities and BioTopLite 2 as a domain top-level ontology. General rules for the TNM classification system and the specific TNM classification for colorectal tumours were axiomatised in description logic. Case-based information was collected from tumour documentation practice in the Comprehensive Cancer Centre of a large university hospital. Based on the ontology, a module was developed that classifies pathology data. TNM was represented as an information artefact, which consists of single representational units. Corresponding to every representational unit, tumours and tumour aggregates were defined. Tumour aggregates consist of the primary tumour and, if existing, of infiltrated regional lymph nodes and distant metastases. TNM codes depend on the location and certain qualities of the primary tumour (T), the infiltrated regional lymph nodes (N) and the existence of distant metastases (M). Tumour data from clinical and pathological documentation were successfully classified with the ontology. A first version of the TNM Ontology represents the TNM system for the description of the anatomical extent of malignant tumours. The present work demonstrates its representational power and completeness as well as its applicability for classification of instance data.

A Bayesian approach to the creation of a study-customized neonatal brain atlas

PubMed Central

Zhang, Yajing; Chang, Linda; Ceritoglu, Can; Skranes, Jon; Ernst, Thomas; Mori, Susumu; Miller, Michael I.; Oishi, Kenichi

2014-01-01

Atlas-based image analysis (ABA), in which an anatomical “parcellation map” is used for parcel-by-parcel image quantification, is widely used to analyze anatomical and functional changes related to brain development, aging, and various diseases. The parcellation maps are often created based on common MRI templates, which allow users to transform the template to target images, or vice versa, to perform parcel-by-parcel statistics, and report the scientific findings based on common anatomical parcels. The use of a study-specific template, which represents the anatomical features of the study population better than common templates, is preferable for accurate anatomical labeling; however, the creation of a parcellation map for a study-specific template is extremely labor intensive, and the definitions of anatomical boundaries are not necessarily compatible with those of the common template. In this study, we employed a Volume-based Template Estimation (VTE) method to create a neonatal brain template customized to a study population, while keeping the anatomical parcellation identical to that of a common MRI atlas. The VTE was used to morph the standardized parcellation map of the JHU-neonate-SS atlas to capture the anatomical features of a study population. The resultant “study-customized” T1-weighted and diffusion tensor imaging (DTI) template, with three-dimensional anatomical parcellation that defined 122 brain regions, was compared with the JHU-neonate-SS atlas, in terms of the registration accuracy. A pronounced increase in the accuracy of cortical parcellation and superior tensor alignment were observed when the customized template was used. With the customized atlas-based analysis, the fractional anisotropy (FA) detected closely approximated the manual measurements. This tool provides a solution for achieving normalization-based measurements with increased accuracy, while reporting scientific findings in a consistent framework. PMID:25026155

Coupling of a finite element human head model with a lumped parameter Hybrid III dummy model: preliminary results.

PubMed

Ruan, J S; Prasad, P

1995-08-01

A skull-brain finite element model of the human head has been coupled with a multilink rigid body model of the Hybrid III dummy. The experimental coupled model is intended to represent anatomically a 50th percentile human to the extent the dummy and the skull-brain model represent a human. It has been verified by simulating several human cadaver head impact tests as well as dummy head 'impacts" during barrier crashes in an automotive environment. Skull-isostress and brain-isostrain response curves were established based on model calibration of experimental human cadaver tolerance data. The skull-isostress response curve agrees with the JARI Human Head Impact Tolerance Curve for skull fracture. The brain-isostrain response curve predicts a higher G level for concussion than does the JARI concussion curve and the Wayne State Tolerance Curve at the longer time duration range. Barrier crash simulations consist of belted dummies impacting an airbag, a hard and soft steering wheel hub, and no head contact with vehicle interior components. Head impact force, intracranial pressures and strains, skull stress, and head center-of-gravity acceleration were investigated as injury parameters. Head injury criterion (HIC) was also calculated along with these parameters. Preliminary results of the model simulations in those impact conditions are discussed.

A simple method for EEG guided transcranial electrical stimulation without models.

PubMed

Cancelli, Andrea; Cottone, Carlo; Tecchio, Franca; Truong, Dennis Q; Dmochowski, Jacek; Bikson, Marom

2016-06-01

There is longstanding interest in using EEG measurements to inform transcranial Electrical Stimulation (tES) but adoption is lacking because users need a simple and adaptable recipe. The conventional approach is to use anatomical head-models for both source localization (the EEG inverse problem) and current flow modeling (the tES forward model), but this approach is computationally demanding, requires an anatomical MRI, and strict assumptions about the target brain regions. We evaluate techniques whereby tES dose is derived from EEG without the need for an anatomical head model, target assumptions, difficult case-by-case conjecture, or many stimulation electrodes. We developed a simple two-step approach to EEG-guided tES that based on the topography of the EEG: (1) selects locations to be used for stimulation; (2) determines current applied to each electrode. Each step is performed based solely on the EEG with no need for head models or source localization. Cortical dipoles represent idealized brain targets. EEG-guided tES strategies are verified using a finite element method simulation of the EEG generated by a dipole, oriented either tangential or radial to the scalp surface, and then simulating the tES-generated electric field produced by each model-free technique. These model-free approaches are compared to a 'gold standard' numerically optimized dose of tES that assumes perfect understanding of the dipole location and head anatomy. We vary the number of electrodes from a few to over three hundred, with focality or intensity as optimization criterion. Model-free approaches evaluated include (1) voltage-to-voltage, (2) voltage-to-current; (3) Laplacian; and two Ad-Hoc techniques (4) dipole sink-to-sink; and (5) sink to concentric. Our results demonstrate that simple ad hoc approaches can achieve reasonable targeting for the case of a cortical dipole, remarkably with only 2-8 electrodes and no need for a model of the head. Our approach is verified directly only for a theoretically localized source, but may be potentially applied to an arbitrary EEG topography. For its simplicity and linearity, our recipe for model-free EEG guided tES lends itself to broad adoption and can be applied to static (tDCS), time-variant (e.g., tACS, tRNS, tPCS), or closed-loop tES.

A simple method for EEG guided transcranial electrical stimulation without models

NASA Astrophysics Data System (ADS)

Cancelli, Andrea; Cottone, Carlo; Tecchio, Franca; Truong, Dennis Q.; Dmochowski, Jacek; Bikson, Marom

2016-06-01

Objective. There is longstanding interest in using EEG measurements to inform transcranial Electrical Stimulation (tES) but adoption is lacking because users need a simple and adaptable recipe. The conventional approach is to use anatomical head-models for both source localization (the EEG inverse problem) and current flow modeling (the tES forward model), but this approach is computationally demanding, requires an anatomical MRI, and strict assumptions about the target brain regions. We evaluate techniques whereby tES dose is derived from EEG without the need for an anatomical head model, target assumptions, difficult case-by-case conjecture, or many stimulation electrodes. Approach. We developed a simple two-step approach to EEG-guided tES that based on the topography of the EEG: (1) selects locations to be used for stimulation; (2) determines current applied to each electrode. Each step is performed based solely on the EEG with no need for head models or source localization. Cortical dipoles represent idealized brain targets. EEG-guided tES strategies are verified using a finite element method simulation of the EEG generated by a dipole, oriented either tangential or radial to the scalp surface, and then simulating the tES-generated electric field produced by each model-free technique. These model-free approaches are compared to a ‘gold standard’ numerically optimized dose of tES that assumes perfect understanding of the dipole location and head anatomy. We vary the number of electrodes from a few to over three hundred, with focality or intensity as optimization criterion. Main results. Model-free approaches evaluated include (1) voltage-to-voltage, (2) voltage-to-current; (3) Laplacian; and two Ad-Hoc techniques (4) dipole sink-to-sink; and (5) sink to concentric. Our results demonstrate that simple ad hoc approaches can achieve reasonable targeting for the case of a cortical dipole, remarkably with only 2-8 electrodes and no need for a model of the head. Significance. Our approach is verified directly only for a theoretically localized source, but may be potentially applied to an arbitrary EEG topography. For its simplicity and linearity, our recipe for model-free EEG guided tES lends itself to broad adoption and can be applied to static (tDCS), time-variant (e.g., tACS, tRNS, tPCS), or closed-loop tES.

The light response of mesophyll conductance is controlled by structure across leaf profiles.

PubMed

Théroux-Rancourt, Guillaume; Gilbert, Matthew E

2017-05-01

Mesophyll conductance to CO 2 (g m ) may respond to light either through regulated dynamic mechanisms or due to anatomical and structural factors. At low light, some layers of cells in the leaf cross-section approach photocompensation and contribute minimally to bulk leaf photosynthesis and little to whole leaf g m (g m,leaf ). Thus, the bulk g m,leaf will appear to respond to light despite being based upon cells having an anatomically fixed mesophyll conductance. Such behaviour was observed in species with contrasting leaf structure using the variable J or stable isotope method of measuring g m,leaf . A species with bifacial structure, Arbutus × 'Marina', and an isobilateral species, Triticum durum L., had contrasting responses of g m,leaf upon varying adaxial or abaxial illumination. Anatomical observations, when coupled with the proposed model of g m,leaf to photosynthetic photon flux density (PPFD) response, successfully represented the observed gas exchange data. The theoretical and observed evidence that g m,leaf apparently responds to light has large implications for how g m,leaf values are interpreted, particularly limitation analyses, and indicates the importance of measuring g m under full light saturation. Responses of g m,leaf to the environment should be treated as an emergent property of a distributed 3D structure, and not solely a leaf area-based phenomenon. © 2016 John Wiley & Sons Ltd.

Anatomically accurate high resolution modeling of human whole heart electromechanics: A strongly scalable algebraic multigrid solver method for nonlinear deformation

NASA Astrophysics Data System (ADS)

Augustin, Christoph M.; Neic, Aurel; Liebmann, Manfred; Prassl, Anton J.; Niederer, Steven A.; Haase, Gundolf; Plank, Gernot

2016-01-01

Electromechanical (EM) models of the heart have been used successfully to study fundamental mechanisms underlying a heart beat in health and disease. However, in all modeling studies reported so far numerous simplifications were made in terms of representing biophysical details of cellular function and its heterogeneity, gross anatomy and tissue microstructure, as well as the bidirectional coupling between electrophysiology (EP) and tissue distension. One limiting factor is the employed spatial discretization methods which are not sufficiently flexible to accommodate complex geometries or resolve heterogeneities, but, even more importantly, the limited efficiency of the prevailing solver techniques which is not sufficiently scalable to deal with the incurring increase in degrees of freedom (DOF) when modeling cardiac electromechanics at high spatio-temporal resolution. This study reports on the development of a novel methodology for solving the nonlinear equation of finite elasticity using human whole organ models of cardiac electromechanics, discretized at a high para-cellular resolution. Three patient-specific, anatomically accurate, whole heart EM models were reconstructed from magnetic resonance (MR) scans at resolutions of 220 μm, 440 μm and 880 μm, yielding meshes of approximately 184.6, 24.4 and 3.7 million tetrahedral elements and 95.9, 13.2 and 2.1 million displacement DOF, respectively. The same mesh was used for discretizing the governing equations of both electrophysiology (EP) and nonlinear elasticity. A novel algebraic multigrid (AMG) preconditioner for an iterative Krylov solver was developed to deal with the resulting computational load. The AMG preconditioner was designed under the primary objective of achieving favorable strong scaling characteristics for both setup and solution runtimes, as this is key for exploiting current high performance computing hardware. Benchmark results using the 220 μm, 440 μm and 880 μm meshes demonstrate efficient scaling up to 1024, 4096 and 8192 compute cores which allowed the simulation of a single heart beat in 44.3, 87.8 and 235.3 minutes, respectively. The efficiency of the method allows fast simulation cycles without compromising anatomical or biophysical detail.

Anatomically accurate high resolution modeling of human whole heart electromechanics: A strongly scalable algebraic multigrid solver method for nonlinear deformation

PubMed Central

Augustin, Christoph M.; Neic, Aurel; Liebmann, Manfred; Prassl, Anton J.; Niederer, Steven A.; Haase, Gundolf; Plank, Gernot

2016-01-01

Electromechanical (EM) models of the heart have been used successfully to study fundamental mechanisms underlying a heart beat in health and disease. However, in all modeling studies reported so far numerous simplifications were made in terms of representing biophysical details of cellular function and its heterogeneity, gross anatomy and tissue microstructure, as well as the bidirectional coupling between electrophysiology (EP) and tissue distension. One limiting factor is the employed spatial discretization methods which are not sufficiently flexible to accommodate complex geometries or resolve heterogeneities, but, even more importantly, the limited efficiency of the prevailing solver techniques which are not sufficiently scalable to deal with the incurring increase in degrees of freedom (DOF) when modeling cardiac electromechanics at high spatio-temporal resolution. This study reports on the development of a novel methodology for solving the nonlinear equation of finite elasticity using human whole organ models of cardiac electromechanics, discretized at a high para-cellular resolution. Three patient-specific, anatomically accurate, whole heart EM models were reconstructed from magnetic resonance (MR) scans at resolutions of 220 μm, 440 μm and 880 μm, yielding meshes of approximately 184.6, 24.4 and 3.7 million tetrahedral elements and 95.9, 13.2 and 2.1 million displacement DOF, respectively. The same mesh was used for discretizing the governing equations of both electrophysiology (EP) and nonlinear elasticity. A novel algebraic multigrid (AMG) preconditioner for an iterative Krylov solver was developed to deal with the resulting computational load. The AMG preconditioner was designed under the primary objective of achieving favorable strong scaling characteristics for both setup and solution runtimes, as this is key for exploiting current high performance computing hardware. Benchmark results using the 220 μm, 440 μm and 880 μm meshes demonstrate efficient scaling up to 1024, 4096 and 8192 compute cores which allowed the simulation of a single heart beat in 44.3, 87.8 and 235.3 minutes, respectively. The efficiency of the method allows fast simulation cycles without compromising anatomical or biophysical detail. PMID:26819483

A Spine Loading Model of Women in the Military

DTIC Science & Technology

1999-10-01

Table 1.8. Left erector spinae anatomical cross-sectional areas ..................................... 42 Table 1.9. Right rectus abdominis anatomical...cross-sectional areas ................................ 43 Table 1.10. Left rectus abdominis anatomical cross-sectional areas...Right rectus abdominis coronal plane moment-arms ....................................... 59 Table 1.26. Left rectus abdominis coronal plane moment-arms

The evolution of anatomical illustration and wax modelling in Italy from the 16th to early 19th centuries

PubMed Central

Riva, Alessandro; Conti, Gabriele; Solinas, Paola; Loy, Francesco

2010-01-01

Although the contribution to anatomical illustration by Vesalius and his followers has received much attention, less credit has been given to Veslingius and particularly Fabricius. By 1600, Fabricius had amassed more than 300 paintings that together made the Tabulae Pictae, a great atlas of anatomy that was highly admired by his contemporaries. Many of his new observations were incorporated into subsequent books, including those by Casserius, Spighelius, Harvey and Veslingius. Also of importance were the Tabulae by Eustachius (1552), which, although only published in 1714, greatly influenced anatomical wax modelling. In 1742, Pope Benedict XIV established a Museum of Anatomy in Bologna, entrusting to Ercole Lelli the creation of several anatomical preparations in wax. Felice Fontana realised that the production of a large number of models by the casting method would make cadaveric specimens superfluous for anatomical teaching and in 1771 he asked the Grand Duke to fund a wax-modelling workshop in Florence as part of the Natural History Museum, later known as La Specola. Fontana engaged Giuseppe Ferrini as his first modeller and then the 19-year-old Clemente Susini who, by his death in 1814, had superintended the production of, or personally made, more than 2000 models. In 1780, the Austrian Emperor Joseph II visited La Specola and ordered a great number of models for his Josephinum museum; these were made by Fontana with the help of Clemente Susini and supervised by the anatomist Paolo Mascagni. It is, however, in Cagliari that some of Susini’s greatest waxes are to be found. These were made when he was free of Fontana’s influence and were based on dissections made by Francesco Antonio Boi (University of Cagliari). Their distinctive anatomical features include the emphasis given to nerves and the absence of lymphatics in the brain, a mistake made on earlier waxes. The refined technical perfection of the anatomical details demonstrates the closeness of the cooperation between Susini and Boi, whereas the expressiveness of the faces and the harmony of colours make the models of Cagliari masterpieces of figurative art. PMID:19900181

An Anatomically Constrained, Stochastic Model of Eye Movement Control in Reading

ERIC Educational Resources Information Center

McDonald, Scott A.; Carpenter, R. H. S.; Shillcock, Richard C.

2005-01-01

This article presents SERIF, a new model of eye movement control in reading that integrates an established stochastic model of saccade latencies (LATER; R. H. S. Carpenter, 1981) with a fundamental anatomical constraint on reading: the vertically split fovea and the initial projection of information in either visual field to the contralateral…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moignier, Alexandra, E-mail: alexandra.moignier@irsn.fr; Derreumaux, Sylvie; Broggio, David

Purpose: Current retrospective cardiovascular dosimetry studies are based on a representative patient or simple mathematic phantoms. Here, a process of patient modeling was developed to personalize the anatomy of the thorax and to include a heart model with coronary arteries. Methods and Materials: The patient models were hybrid computational phantoms (HCPs) with an inserted detailed heart model. A computed tomography (CT) acquisition (pseudo-CT) was derived from HCP and imported into a treatment planning system where treatment conditions were reproduced. Six current patients were selected: 3 were modeled from their CT images (A patients) and the others were modelled from 2more » orthogonal radiographs (B patients). The method performance and limitation were investigated by quantitative comparison between the initial CT and the pseudo-CT, namely, the morphology and the dose calculation were compared. For the B patients, a comparison with 2 kinds of representative patients was also conducted. Finally, dose assessment was focused on the whole coronary artery tree and the left anterior descending coronary. Results: When 3-dimensional anatomic information was available, the dose calculations performed on the initial CT and the pseudo-CT were in good agreement. For the B patients, comparison of doses derived from HCP and representative patients showed that the HCP doses were either better or equivalent. In the left breast radiation therapy context and for the studied cases, coronary mean doses were at least 5-fold higher than heart mean doses. Conclusions: For retrospective dose studies, it is suggested that HCP offers a better surrogate, in terms of dose accuracy, than representative patients. The use of a detailed heart model eliminates the problem of identifying the coronaries on the patient's CT.« less

Presentation of Anatomical Variations Using the Aurasma Mobile App

PubMed Central

Bézard, Georg; Lozanoff, Beth K; Labrash, Steven; Lozanoff, Scott

2015-01-01

Knowledge of anatomical variations is critical to avoid clinical complications and it enables an understanding of morphogenetic mechanisms. Depictions are comprised of photographs or illustrations often limiting appreciation of three-dimensional (3D) spatial relationships. The purpose of this study is to describe an approach for presenting anatomical variations utilizing video clips emphasizing 3D anatomical relationships delivered on personal electronic devices. An aberrant right subclavian artery (ARSA) was an incidental finding in a routine dissection of an 89-year-old man cadaver during a medical student instructional laboratory. The specimen was photographed and physical measurements were recorded. Three-dimensional models were lofted and rendered with Maya software and converted as Quicktime animations. Photographs of the first frame of the animations were recorded and registered with Aurasma Mobile App software (www.aurasma.com). Resulting animations were viewed on mobile devices. The ARSA model can be manipulated on the mobile device enabling the student to view and appreciate spatial relationships. Model elements can be de-constructed to provide even greater spatial resolution of anatomical relationships. Animations provide a useful approach for visualizing anatomical variations. Future work will be directed at creating a library of variants and underlying mechanism of formation for presentation through the Aurasma application. PMID:26793410

Remodelling of cellular excitation (reaction) and intercellular coupling (diffusion) by chronic atrial fibrillation represented by a reaction-diffusion system

NASA Astrophysics Data System (ADS)

Zhang, Henggui; Garratt, Clifford J.; Kharche, Sanjay; Holden, Arun V.

2009-06-01

Human atrial tissue is an excitable system, in which myocytes are excitable elements, and cell-to-cell electrotonic interactions are via diffusive interactions of cell membrane potentials. We developed a family of excitable system models for human atrium at cellular, tissue and anatomical levels for both normal and chronic atrial fibrillation (AF) conditions. The effects of AF-induced remodelling of cell membrane ionic channels (reaction kinetics) and intercellular gap junctional coupling (diffusion) on atrial excitability, conduction of excitation waves and dynamics of re-entrant excitation waves are quantified. Both ionic channel and gap junctional coupling remodelling have rate dependent effects on atrial propagation. Membrane channel conductance remodelling allows the propagation of activity at higher rates than those sustained in normal tissue or in tissue with gap junctional remodelling alone. Membrane channel conductance remodelling is essential for the propagation of activity at rates higher than 300/min as seen in AF. Spatially heterogeneous gap junction coupling remodelling increased the risk of conduction block, an essential factor for the genesis of re-entry. In 2D and 3D anatomical models, the dynamical behaviours of re-entrant excitation waves are also altered by membrane channel modelling. This study provides insights to understand the pro-arrhythmic effects of AF-induced reaction and diffusion remodelling in atrial tissue.

Cell tracing reveals a dorsoventral lineage restriction plane in the mouse limb bud mesenchyme.

PubMed

Arques, Carlos G; Doohan, Roisin; Sharpe, James; Torres, Miguel

2007-10-01

Regionalization of embryonic fields into independent units of growth and patterning is a widespread strategy during metazoan development. Compartments represent a particular instance of this regionalization, in which unit coherence is maintained by cell lineage restriction between adjacent regions. Lineage compartments have been described during insect and vertebrate development. Two common characteristics of the compartments described so far are their occurrence in epithelial structures and the presence of signaling regions at compartment borders. Whereas Drosophila compartmental organization represents a background subdivision of embryonic fields that is not necessarily related to anatomical structures, vertebrate compartment borders described thus far coincide with, or anticipate, anatomical or cell-type discontinuities. Here, we describe a general method for clonal analysis in the mouse and use it to determine the topology of clone distribution along the three limb axes. We identify a lineage restriction boundary at the limb mesenchyme dorsoventral border that is unrelated to any anatomical discontinuity, and whose lineage restriction border is not obviously associated with any signaling center. This restriction is the first example in vertebrates of a mechanism of primordium subdivision unrelated to anatomical boundaries. Furthermore, this is the first lineage compartment described within a mesenchymal structure in any organism, suggesting that lineage restrictions are fundamental not only for epithelial structures, but also for mesenchymal field patterning. No lineage compartmentalization was found along the proximodistal or anteroposterior axes, indicating that patterning along these axes does not involve restriction of cell dispersion at specific axial positions.

Severity scores in trauma patients admitted to ICU. Physiological and anatomic models.

PubMed

Serviá, L; Badia, M; Montserrat, N; Trujillano, J

2018-02-02

The goals of this project were to compare both the anatomic and physiologic severity scores in trauma patients admitted to intensive care unit (ICU), and to elaborate mixed statistical models to improve the precision of the scores. A prospective study of cohorts. The combined medical/surgical ICU in a secondary university hospital. Seven hundred and eighty trauma patients admitted to ICU older than 16 years of age. Anatomic models (ISS and NISS) were compared and combined with physiological models (T-RTS, APACHE II [APII], and MPM II). The probability of death was calculated following the TRISS method. The discrimination was assessed using ROC curves (ABC [CI 95%]), and the calibration using the Hosmer-Lemeshoẃs H test. The mixed models were elaborated with the tree classification method type Chi Square Automatic Interaction Detection. A 14% global mortality was recorded. The physiological models presented the best discrimination values (APII of 0.87 [0.84-0.90]). All models were affected by bad calibration (P<.01). The best mixed model resulted from the combination of APII and ISS (0.88 [0.83-0.90]). This model was able to differentiate between a 7.5% mortality for elderly patients with pathological antecedents and a 25% mortality in patients presenting traumatic brain injury, from a pool of patients with APII values ranging from 10 to 17 and an ISS threshold of 22. The physiological models perform better than the anatomical models in traumatic patients admitted to the ICU. Patients with low scores in the physiological models require an anatomic analysis of the injuries to determine their severity. Copyright © 2017 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

[Results from the German shoulder- and elbow arthroplasty register (SEPR) : Anatomic or reverse shoulder arthroplasty in B2-glenoids?

PubMed

Magosch, P; Habermeyer, P; Lichtenberg, S; Tauber, M; Gohlke, F; Mauch, F; Boehm, D; Loew, M; Zeifang, F; Pötzl, W

2017-12-01

Anatomic shoulder arthroplasty in osteoarthritis with biconcave glenoid wear results in decreased functional results and a higher rate of early glenoid loosening. The aim of the data analysis of the German shoulder arthroplasty register was to clarify whether reverse shoulder arthroplasty can provide better functional results and a lower complication rate than anatomic arthroplasty in osteoarthritis with biconcave glenoid wear. The analysis included 1052 completely documented primary implanted arthroplasties with a minimum follow-up of 2 years. In 119 cases, a B2-type glenoid was present. Out of these cases, 86 were treated with an anatomic shoulder arthroplasty, and in 33 cases a reverse shoulder arthroplasty was implanted. The mean follow-up was 47.6 months. The Constant score with its subcategories, as well as the active range of movement improved significantly after anatomic and after reverse shoulder arthroplasty. We observed no difference in functional results between both types of arthroplasty; however, reverse arthroplasty showed a significant higher revision rate (21.2%) (3% glenoid loosening, 6% prosthetic instability) than anatomic shoulder arthroplasty (12.8%) (11.6% glenoid loosening, 1.2% prosthetic instability), whereas anatomic shoulder arthroplasty showed a higher rate of glenoid loosening. Functional and radiographic results of both types of arthroplasty are comparable with the results reported in the literature, although our analysis represents results from an implant registry (data pertaining to medical care quality).

Local tissue air ratio in an anatomic phantom for 60Co total body irradiation.

PubMed

Vrtar, M; Purisić, A

1991-07-01

Tissue-air ratio (TAR), as the basic dosimetric function, is not ideally applicable to all important locations in total body irradiation (TBI) dosimetry because it generally refers to central ray measurements. We therefore introduced the local TAR which depends on the specific distribution of the scattering centres around the location of interest. Local TAR measurements were performed in an anatomic water phantom, produced by a sculptor, representing a patient during TBI in the real treatment position. A comparison has been made between TAR values, defined on the beam's ray at different locations in the anatomic phantom and cubic phantoms of different size. The local TAR values in the anatomic phantom, having more realistic outer surface curvatures, are lower by a few percent in most locations. We consider these values more accurate and better applicable to TBI conditions than those obtained in cubic water phantoms, even if the volume of the phantom is adapted to the particular side of the body.

Viewpoint: exploring the human interior: the roles of cadaver dissection and radiologic imaging in teaching anatomy.

PubMed

Gunderman, Richard B; Wilson, Philip K

2005-08-01

For a variety of reasons, new radiological imaging techniques are supplanting traditional cadaver dissection in the teaching of human anatomy. The authors briefly review the historical forces behind this transition, and then explore the advantages and drawbacks of each approach. Cadaver dissection offers an active, hands-on exploration of human structure, provides deep insights into the meaning of human embodiment and mortality, and represents a profound rite of passage into the medical profession. Radiological imaging permits in vivo visualization, offers physiologic as well as anatomic insights, and represents the context in which contemporary practicing physicians most frequently encounter their patients' otherwise hidden internal anatomy. Despite its important strengths, radiology cannot simply substitute for cadaver dissection, and the best models for teaching gross anatomy will incorporate both cadaver dissection and radiological imaging.

Investigating implicit knowledge in ontologies with application to the anatomical domain.

PubMed

Zhang, S; Bodenreider, O

2004-01-01

Knowledge in biomedical ontologies can be explicitly represented (often by means of semantic relations), but may also be implicit, i.e., embedded in the concept names and inferable from various combinations of semantic relations. This paper investigates implicit knowledge in two ontologies of anatomy: the Foundational Model of Anatomy and GALEN. The methods consist of extracting the knowledge explicitly represented, acquiring the implicit knowledge through augmentation and inference techniques, and identifying the origin of each semantic relation. The number of relations (12 million in FMA and 4.6 million in GALEN), broken down by source, is presented. Major findings include: each technique provides specific relations; and many relations can be generated by more than one technique. The application of these findings to ontology auditing, validation, and maintenance is discussed, as well as the application to ontology integration.

Recovery of directed intracortical connectivity from fMRI data

NASA Astrophysics Data System (ADS)

Gilson, Matthieu; Ritter, Petra; Deco, Gustavo

2016-06-01

The brain exhibits complex spatio-temporal patterns of activity. In particular, its baseline activity at rest has a specific structure: imaging techniques (e.g., fMRI, EEG and MEG) show that cortical areas experience correlated fluctuations, which is referred to as functional connectivity (FC). The present study relies on our recently developed model in which intracortical white-matter connections shape noise-driven fluctuations to reproduce FC observed in experimental data (here fMRI BOLD signal). Here noise has a functional role and represents the variability of neural activity. The model also incorporates anatomical information obtained using diffusion tensor imaging (DTI), which estimates the density of white-matter fibers (structural connectivity, SC). After optimization to match empirical FC, the model provides an estimation of the efficacies of these fibers, which we call effective connectivity (EC). EC differs from SC, as EC not only accounts for the density of neural fibers, but also the concentration of synapses formed at their end, the type of neurotransmitters associated and the excitability of target neural populations. In summary, the model combines anatomical SC and activity FC to evaluate what drives the neural dynamics, embodied in EC. EC can then be analyzed using graph theory to understand how it generates FC and to seek for functional communities among cortical areas (parcellation of 68 areas). We find that intracortical connections are not symmetric, which affects the dynamic range of cortical activity (i.e., variety of states it can exhibit).

Defining the essential anatomical coverage provided by military body armour against high energy projectiles.

PubMed

Breeze, John; Lewis, E A; Fryer, R; Hepper, A E; Mahoney, Peter F; Clasper, Jon C

2016-08-01

Body armour is a type of equipment worn by military personnel that aims to prevent or reduce the damage caused by ballistic projectiles to structures within the thorax and abdomen. Such injuries remain the leading cause of potentially survivable deaths on the modern battlefield. Recent developments in computer modelling in conjunction with a programme to procure the next generation of UK military body armour has provided the impetus to re-evaluate the optimal anatomical coverage provided by military body armour against high energy projectiles. A systematic review of the literature was undertaken to identify those anatomical structures within the thorax and abdomen that if damaged were highly likely to result in death or significant long-term morbidity. These structures were superimposed upon two designs of ceramic plate used within representative body armour systems using a computerised representation of human anatomy. Those structures requiring essential medical coverage by a plate were demonstrated to be the heart, great vessels, liver and spleen. For the 50th centile male anthropometric model used in this study, the front and rear plates from the Enhanced Combat Body Armour system only provide limited coverage, but do fulfil their original requirement. The plates from the current Mark 4a OSPREY system cover all of the structures identified in this study as requiring coverage except for the abdominal sections of the aorta and inferior vena cava. Further work on sizing of plates is recommended due to its potential to optimise essential medical coverage. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

A multi-resolution strategy for a multi-objective deformable image registration framework that accommodates large anatomical differences

NASA Astrophysics Data System (ADS)

Alderliesten, Tanja; Bosman, Peter A. N.; Sonke, Jan-Jakob; Bel, Arjan

2014-03-01

Currently, two major challenges dominate the field of deformable image registration. The first challenge is related to the tuning of the developed methods to specific problems (i.e. how to best combine different objectives such as similarity measure and transformation effort). This is one of the reasons why, despite significant progress, clinical implementation of such techniques has proven to be difficult. The second challenge is to account for large anatomical differences (e.g. large deformations, (dis)appearing structures) that occurred between image acquisitions. In this paper, we study a framework based on multi-objective optimization to improve registration robustness and to simplify tuning for specific applications. Within this framework we specifically consider the use of an advanced model-based evolutionary algorithm for optimization and a dual-dynamic transformation model (i.e. two "non-fixed" grids: one for the source- and one for the target image) to accommodate for large anatomical differences. The framework computes and presents multiple outcomes that represent efficient trade-offs between the different objectives (a so-called Pareto front). In image processing it is common practice, for reasons of robustness and accuracy, to use a multi-resolution strategy. This is, however, only well-established for single-objective registration methods. Here we describe how such a strategy can be realized for our multi-objective approach and compare its results with a single-resolution strategy. For this study we selected the case of prone-supine breast MRI registration. Results show that the well-known advantages of a multi-resolution strategy are successfully transferred to our multi-objective approach, resulting in superior (i.e. Pareto-dominating) outcomes.

A biomechanical assessment of isometric handgrip force and fatigue at different anatomical positions.

PubMed

Alkurdi, Ziad D; Dweiri, Yazan M

2010-05-01

The present work examined the handgrip force at different anatomical positions for both hands. Anthropometrics, handgrip force, and fatigue were obtained from a representative sample of 20 males randomly selected from the German Jordanian University students. The hand dynamometer first was calibrated with respect to the volunteer's maximal grip strength, and he was then asked to squeeze maximally until the grip force decreased to 50% of its maximal due to fatigue; this test was performed for both hands at different anatomical positions with 2 min of rest for recovery of muscle function. The results showed differences in the handgrip force between subjects of the same anatomical positions and for the different anatomical positions, differences in the time for 50% of the force maximal for both right hand and left hand, higher time required to achieve 50% of maximal handgrip force for the nondominant hand, and maximal handgrip force was obtained when arm adduction with 90 degrees forward at the elbow joint. Recommendations for future work are to measure fatigue time at different percentages, 25%, 50%, 60%, and 75% of maximal force and to investigate the factors affecting handgrip force over a larger sample.

Decoupling function and anatomy in atlases of functional connectivity patterns: language mapping in tumor patients.

PubMed

Langs, Georg; Sweet, Andrew; Lashkari, Danial; Tie, Yanmei; Rigolo, Laura; Golby, Alexandra J; Golland, Polina

2014-12-01

In this paper we construct an atlas that summarizes functional connectivity characteristics of a cognitive process from a population of individuals. The atlas encodes functional connectivity structure in a low-dimensional embedding space that is derived from a diffusion process on a graph that represents correlations of fMRI time courses. The functional atlas is decoupled from the anatomical space, and thus can represent functional networks with variable spatial distribution in a population. In practice the atlas is represented by a common prior distribution for the embedded fMRI signals of all subjects. We derive an algorithm for fitting this generative model to the observed data in a population. Our results in a language fMRI study demonstrate that the method identifies coherent and functionally equivalent regions across subjects. The method also successfully maps functional networks from a healthy population used as a training set to individuals whose language networks are affected by tumors. Copyright © 2014. Published by Elsevier Inc.

Solid object visualization of 3D ultrasound data

NASA Astrophysics Data System (ADS)

Nelson, Thomas R.; Bailey, Michael J.

2000-04-01

Visualization of volumetric medical data is challenging. Rapid-prototyping (RP) equipment producing solid object prototype models of computer generated structures is directly applicable to visualization of medical anatomic data. The purpose of this study was to develop methods for transferring 3D Ultrasound (3DUS) data to RP equipment for visualization of patient anatomy. 3DUS data were acquired using research and clinical scanning systems. Scaling information was preserved and the data were segmented using threshold and local operators to extract features of interest, converted from voxel raster coordinate format to a set of polygons representing an iso-surface and transferred to the RP machine to create a solid 3D object. Fabrication required 30 to 60 minutes depending on object size and complexity. After creation the model could be touched and viewed. A '3D visualization hardcopy device' has advantages for conveying spatial relations compared to visualization using computer display systems. The hardcopy model may be used for teaching or therapy planning. Objects may be produced at the exact dimension of the original object or scaled up (or down) to facilitate matching the viewers reference frame more optimally. RP models represent a useful means of communicating important information in a tangible fashion to patients and physicians.

The New York Head—A precise standardized volume conductor model for EEG source localization and tES targeting

PubMed Central

Huang, Yu; Parra, Lucas C.; Haufe, Stefan

2018-01-01

In source localization of electroencephalograpic (EEG) signals, as well as in targeted transcranial electric current stimulation (tES), a volume conductor model is required to describe the flow of electric currents in the head. Boundary element models (BEM) can be readily computed to represent major tissue compartments, but cannot encode detailed anatomical information within compartments. Finite element models (FEM) can capture more tissue types and intricate anatomical structures, but with the higher precision also comes the need for semiautomated segmentation, and a higher computational cost. In either case, adjusting to the individual human anatomy requires costly magnetic resonance imaging (MRI), and thus head modeling is often based on the anatomy of an ‘arbitrary’ individual (e.g. Colin27). Additionally, existing reference models for the human head often do not include the cerebrospinal fluid (CSF), and their field of view excludes portions of the head and neck—two factors that demonstrably affect current-flow patterns. Here we present a highly detailed FEM, which we call ICBM-NY, or “New York Head”. It is based on the ICBM152 anatomical template (a non-linear average of the MRI of 152 adult human brains) defined in MNI coordinates, for which we extended the field of view to the neck and performed a detailed segmentation of six tissue types (scalp, skull, CSF, gray matter, white matter, air cavities) at 0.5 mm 3 resolution. The model was solved for 231 electrode locations. To evaluate its performance, additional FEMs and BEMs were constructed for four individual subjects. Each of the four individual FEMs (regarded as the ‘ground truth’) is compared to its BEM counterpart, the ICBM-NY, a BEM of the ICBM anatomy, an ‘individualized’ BEM of the ICBM anatomy warped to the individual head surface, and FEMs of the other individuals. Performance is measured in terms of EEG source localization and tES targeting errors. Results show that the ICBM-NY outperforms FEMs of mismatched individual anatomies as well as the BEM of the ICBM anatomy according to both criteria. We therefore propose the New York Head as a new standard head model to be used in future EEG and tES studies whenever an individual MRI is not available. We release all model data online at neuralengr.com/nyhead/ to facilitate broad adoption. PMID:26706450

The New York Head-A precise standardized volume conductor model for EEG source localization and tES targeting.

PubMed

Huang, Yu; Parra, Lucas C; Haufe, Stefan

2016-10-15

In source localization of electroencephalograpic (EEG) signals, as well as in targeted transcranial electric current stimulation (tES), a volume conductor model is required to describe the flow of electric currents in the head. Boundary element models (BEM) can be readily computed to represent major tissue compartments, but cannot encode detailed anatomical information within compartments. Finite element models (FEM) can capture more tissue types and intricate anatomical structures, but with the higher precision also comes the need for semi-automated segmentation, and a higher computational cost. In either case, adjusting to the individual human anatomy requires costly magnetic resonance imaging (MRI), and thus head modeling is often based on the anatomy of an 'arbitrary' individual (e.g. Colin27). Additionally, existing reference models for the human head often do not include the cerebro-spinal fluid (CSF), and their field of view excludes portions of the head and neck-two factors that demonstrably affect current-flow patterns. Here we present a highly detailed FEM, which we call ICBM-NY, or "New York Head". It is based on the ICBM152 anatomical template (a non-linear average of the MRI of 152 adult human brains) defined in MNI coordinates, for which we extended the field of view to the neck and performed a detailed segmentation of six tissue types (scalp, skull, CSF, gray matter, white matter, air cavities) at 0.5mm(3) resolution. The model was solved for 231 electrode locations. To evaluate its performance, additional FEMs and BEMs were constructed for four individual subjects. Each of the four individual FEMs (regarded as the 'ground truth') is compared to its BEM counterpart, the ICBM-NY, a BEM of the ICBM anatomy, an 'individualized' BEM of the ICBM anatomy warped to the individual head surface, and FEMs of the other individuals. Performance is measured in terms of EEG source localization and tES targeting errors. Results show that the ICBM-NY outperforms FEMs of mismatched individual anatomies as well as the BEM of the ICBM anatomy according to both criteria. We therefore propose the New York Head as a new standard head model to be used in future EEG and tES studies whenever an individual MRI is not available. We release all model data online at neuralengr.com/nyhead/ to facilitate broad adoption. Published by Elsevier Inc.

Characterization of Capsicum species using anatomical and molecular data.

PubMed

Dias, G B; Gomes, V M; Moraes, T M S; Zottich, U P; Rabelo, G R; Carvalho, A O; Moulin, M; Gonçalves, L S A; Rodrigues, R; Da Cunha, M

2013-02-28

Capsicum species are frequently described in terms of genetic divergence, considering morphological, agronomic, and molecular databases. However, descriptions of genetic differences based on anatomical characters are rare. We examined the anatomy and the micromorphology of vegetative and reproductive organs of several Capsicum species. Four Capsicum accessions representing the species C. annuum var. annuum, C. baccatum var. pendulum, C. chinense, and C. frutescens were cultivated in a greenhouse; leaves, fruits and seeds were sampled and their organ structure analyzed by light and scanning electronic microscopy. Molecular accession characterization was made using ISSR markers. Polymorphism was observed among tector trichomes and also in fruit color and shape. High variability among accessions was detected by ISSR markers. Despite the species studied present a wide morphological and molecular variability that was not reflected by anatomical features.

Unification of multi-species vertebrate anatomy ontologies for comparative biology in Uberon

PubMed Central

2014-01-01

Background Elucidating disease and developmental dysfunction requires understanding variation in phenotype. Single-species model organism anatomy ontologies (ssAOs) have been established to represent this variation. Multi-species anatomy ontologies (msAOs; vertebrate skeletal, vertebrate homologous, teleost, amphibian AOs) have been developed to represent ‘natural’ phenotypic variation across species. Our aim has been to integrate ssAOs and msAOs for various purposes, including establishing links between phenotypic variation and candidate genes. Results Previously, msAOs contained a mixture of unique and overlapping content. This hampered integration and coordination due to the need to maintain cross-references or inter-ontology equivalence axioms to the ssAOs, or to perform large-scale obsolescence and modular import. Here we present the unification of anatomy ontologies into Uberon, a single ontology resource that enables interoperability among disparate data and research groups. As a consequence, independent development of TAO, VSAO, AAO, and vHOG has been discontinued. Conclusions The newly broadened Uberon ontology is a unified cross-taxon resource for metazoans (animals) that has been substantially expanded to include a broad diversity of vertebrate anatomical structures, permitting reasoning across anatomical variation in extinct and extant taxa. Uberon is a core resource that supports single- and cross-species queries for candidate genes using annotations for phenotypes from the systematics, biodiversity, medical, and model organism communities, while also providing entities for logical definitions in the Cell and Gene Ontologies. The ontology release files associated with the ontology merge described in this manuscript are available at: http://purl.obolibrary.org/obo/uberon/releases/2013-02-21/ Current ontology release files are available always available at: http://purl.obolibrary.org/obo/uberon/releases/ PMID:25009735

Encoding the local connectivity patterns of fMRI for cognitive task and state classification.

PubMed

Onal Ertugrul, Itir; Ozay, Mete; Yarman Vural, Fatos T

2018-06-15

In this work, we propose a novel framework to encode the local connectivity patterns of brain, using Fisher vectors (FV), vector of locally aggregated descriptors (VLAD) and bag-of-words (BoW) methods. We first obtain local descriptors, called mesh arc descriptors (MADs) from fMRI data, by forming local meshes around anatomical regions, and estimating their relationship within a neighborhood. Then, we extract a dictionary of relationships, called brain connectivity dictionary by fitting a generative Gaussian mixture model (GMM) to a set of MADs, and selecting codewords at the mean of each component of the mixture. Codewords represent connectivity patterns among anatomical regions. We also encode MADs by VLAD and BoW methods using k-Means clustering. We classify cognitive tasks using the Human Connectome Project (HCP) task fMRI dataset and cognitive states using the Emotional Memory Retrieval (EMR). We train support vector machines (SVMs) using the encoded MADs. Results demonstrate that, FV encoding of MADs can be successfully employed for classification of cognitive tasks, and outperform VLAD and BoW representations. Moreover, we identify the significant Gaussians in mixture models by computing energy of their corresponding FV parts, and analyze their effect on classification accuracy. Finally, we suggest a new method to visualize the codewords of the learned brain connectivity dictionary.

Designing learning spaces for interprofessional education in the anatomical sciences.

PubMed

Cleveland, Benjamin; Kvan, Thomas

2015-01-01

This article explores connections between interprofessional education (IPE) models and the design of learning spaces for undergraduate and graduate education in the anatomical sciences and other professional preparation. The authors argue that for IPE models to be successful and sustained they must be embodied in the environment in which interprofessional learning occurs. To elaborate these arguments, two exemplar tertiary education facilities are discussed: the Charles Perkins Centre at the University of Sydney for science education and research, and Victoria University's Interprofessional Clinic in Wyndham for undergraduate IPE in health care. Backed by well-conceived curriculum and pedagogical models, the architectures of these facilities embody the educational visions, methods, and practices they were designed to support. Subsequently, the article discusses the spatial implications of curriculum and pedagogical change in the teaching of the anatomical sciences and explores how architecture might further the development of IPE models in the field. In conclusion, it is argued that learning spaces should be designed and developed (socially) with the expressed intention of supporting collaborative IPE models in health education settings, including those in the anatomical sciences. © 2015 American Association of Anatomists.

A patient-specific model of the biomechanics of hip reduction for neonatal Developmental Dysplasia of the Hip: Investigation of strategies for low to severe grades of Developmental Dysplasia of the Hip.

PubMed

Huayamave, Victor; Rose, Christopher; Serra, Sheila; Jones, Brendan; Divo, Eduardo; Moslehy, Faissal; Kassab, Alain J; Price, Charles T

2015-07-16

A physics-based computational model of neonatal Developmental Dysplasia of the Hip (DDH) following treatment with the Pavlik Harness (PV) was developed to obtain muscle force contribution in order to elucidate biomechanical factors influencing the reduction of dislocated hips. Clinical observation suggests that reduction occurs in deep sleep involving passive muscle action. Consequently, a set of five (5) adductor muscles were identified as mediators of reduction using the PV. A Fung/Hill-type model was used to characterize muscle response. Four grades (1-4) of dislocation were considered, with one (1) being a low subluxation and four (4) a severe dislocation. A three-dimensional model of the pelvis-femur lower limb of a representative 10 week-old female was generated based on CT-scans with the aid of anthropomorphic scaling of anatomical landmarks. The model was calibrated to achieve equilibrium at 90° flexion and 80° abduction. The hip was computationally dislocated according to the grade under investigation, the femur was restrained to move in an envelope consistent with PV restraints, and the dynamic response under passive muscle action and the effect of gravity was resolved. Model results with an anteversion angle of 50° show successful reduction Grades 1-3, while Grade 4 failed to reduce with the PV. These results are consistent with a previous study based on a simplified anatomically-consistent synthetic model and clinical reports of very low success of the PV for Grade 4. However our model indicated that it is possible to achieve reduction of Grade 4 dislocation by hyperflexion and the resultant external rotation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dual-extrusion 3D printing of anatomical models for education.

PubMed

Smith, Michelle L; Jones, James F X

2018-01-01

Two material 3D printing is becoming increasingly popular, inexpensive and accessible. In this paper, freely available printable files and dual extrusion fused deposition modelling were combined to create a number of functional anatomical models. To represent muscle and bone FilaFlex 3D flexible filament and polylactic acid (PLA) filament were extruded respectively via a single 0.4 mm nozzle using a Big Builder printer. For each filament, cubes (5 mm 3 ) were printed and analyzed for X, Y, and Z accuracy. The PLA printed cubes resulted in errors averaging just 1.2% across all directions but for FilaFlex 3D printed cubes the errors were statistically significantly greater (average of 3.2%). As an exemplar, a focus was placed on the muscles, bones and cartilage of upper airway and neck. The resulting single prints combined flexible and hard structures. A single print model of the vocal cords was constructed which permitted movement of the arytenoids on the cricoid cartilage and served to illustrate the action of intrinsic laryngeal muscles. As University libraries become increasingly engaged in offering inexpensive 3D printing services it may soon become common place for both student and educator to access websites, download free models or 3D body parts and only pay the costs of print consumables. Novel models can be manufactured as dissectible, functional multi-layered units and offer rich possibilities for sectional and/or reduced anatomy. This approach can liberate the anatomist from constraints of inflexible hard models or plastinated specimens and engage in the design of class specific models of the future. Anat Sci Educ 11: 65-72. © 2017 American Association of Anatomists. © 2017 American Association of Anatomists.

A review of US anthropometric reference data (1971 2000) with comparisons to both stylized and tomographic anatomic models

NASA Astrophysics Data System (ADS)

Huh, C.; Bolch, W. E.

2003-10-01

Two classes of anatomic models currently exist for use in both radiation protection and radiation dose reconstruction: stylized mathematical models and tomographic voxel models. The former utilize 3D surface equations to represent internal organ structure and external body shape, while the latter are based on segmented CT or MR images of a single individual. While tomographic models are clearly more anthropomorphic than stylized models, a given model's characterization as being anthropometric is dependent upon the reference human to which the model is compared. In the present study, data on total body mass, standing/sitting heights and body mass index are collected and reviewed for the US population covering the time interval from 1971 to 2000. These same anthropometric parameters are then assembled for the ORNL series of stylized models, the GSF series of tomographic models (Golem, Helga, Donna, etc), the adult male Zubal tomographic model and the UF newborn tomographic model. The stylized ORNL models of the adult male and female are found to be fairly representative of present-day average US males and females, respectively, in terms of both standing and sitting heights for ages between 20 and 60-80 years. While the ORNL adult male model provides a reasonably close match to the total body mass of the average US 21-year-old male (within ~5%), present-day 40-year-old males have an average total body mass that is ~16% higher. For radiation protection purposes, the use of the larger 73.7 kg adult ORNL stylized hermaphrodite model provides a much closer representation of average present-day US females at ages ranging from 20 to 70 years. In terms of the adult tomographic models from the GSF series, only Donna (40-year-old F) closely matches her age-matched US counterpart in terms of average body mass. Regarding standing heights, the better matches to US age-correlated averages belong to Irene (32-year-old F) for the females and Golem (38-year-old M) for the males. Both Helga (27-year-old F) and Donna, however, provide good matches to average US sitting heights for adult females, while Golem and Otoko (male of unknown age) yield sitting heights that are slightly below US adult male averages. Finally, Helga is seen as the only GSF tomographic female model that yields a body mass index in line with her average US female counterpart at age 26. In terms of dose reconstruction activities, however, all current tomographic voxel models are valuable assets in attempting to cover the broad distribution of individual anthropometric parameters representative of the current US population. It is highly recommended that similar attempts to create a broad library of tomographic models be initiated in the United States and elsewhere to complement and extend the limited number of tomographic models presently available for these efforts.

How and why does the areole meristem move in Echinocereus (Cactaceae)?

PubMed Central

Sánchez, Daniel; Grego-Valencia, Dalia; Terrazas, Teresa; Arias, Salvador

2015-01-01

Background and Aims In Cactaceae, the areole is the organ that forms the leaves, spines and buds. Apparently, the genus Echinocereus develops enclosed buds that break through the epidermis of the stem adjacent to the areole; this trait most likely represents a synapomorphy of Echinocereus. The development of the areole is investigated here in order to understand the anatomical modifications that lead to internal bud development and to supplement anatomical knowledge of plants that do not behave according to classical shoot theory. Methods The external morphology of the areole was documented and the anatomy was studied using tissue clearing, scanning electron microscopy and light microscopy for 50 species that represent the recognized clades and sections of the traditional classification of the genus, including Morangaya pensilis (Echinocereus pensilis). Key Results In Echinocereus, the areole is sealed by the periderm, and the areole meristem is moved and enclosed by the differential growth of the epidermis and surrounding cortex. The enclosed areole meristem is differentiated in a vegetative or floral bud, which develops internally and breaks through the epidermis of the stem. In Morangaya pensilis, the areole is not sealed by the periderm and the areole meristem is not enclosed. Conclusions The enclosed areole meristem and internal bud development are understood to be an adaptation to protect the meristem and the bud from low temperatures. The anatomical evidence supports the hypothesis that the enclosed bud represents one synapomorphy for Echinocereus and also supports the exclusion of Morangaya from Echinocereus. PMID:25399023

Employing WebGL to develop interactive stereoscopic 3D content for use in biomedical visualization

NASA Astrophysics Data System (ADS)

Johnston, Semay; Renambot, Luc; Sauter, Daniel

2013-03-01

Web Graphics Library (WebGL), the forthcoming web standard for rendering native 3D graphics in a browser, represents an important addition to the biomedical visualization toolset. It is projected to become a mainstream method of delivering 3D online content due to shrinking support for third-party plug-ins. Additionally, it provides a virtual reality (VR) experience to web users accommodated by the growing availability of stereoscopic displays (3D TV, desktop, and mobile). WebGL's value in biomedical visualization has been demonstrated by applications for interactive anatomical models, chemical and molecular visualization, and web-based volume rendering. However, a lack of instructional literature specific to the field prevents many from utilizing this technology. This project defines a WebGL design methodology for a target audience of biomedical artists with a basic understanding of web languages and 3D graphics. The methodology was informed by the development of an interactive web application depicting the anatomy and various pathologies of the human eye. The application supports several modes of stereoscopic displays for a better understanding of 3D anatomical structures.

A feature-based developmental model of the infant brain in structural MRI.

PubMed

Toews, Matthew; Wells, William M; Zöllei, Lilla

2012-01-01

In this paper, anatomical development is modeled as a collection of distinctive image patterns localized in space and time. A Bayesian posterior probability is defined over a random variable of subject age, conditioned on data in the form of scale-invariant image features. The model is automatically learned from a large set of images exhibiting significant variation, used to discover anatomical structure related to age and development, and fit to new images to predict age. The model is applied to a set of 230 infant structural MRIs of 92 subjects acquired at multiple sites over an age range of 8-590 days. Experiments demonstrate that the model can be used to identify age-related anatomical structure, and to predict the age of new subjects with an average error of 72 days.

Data-Driven Sequence of Changes to Anatomical Brain Connectivity in Sporadic Alzheimer's Disease.

PubMed

Oxtoby, Neil P; Garbarino, Sara; Firth, Nicholas C; Warren, Jason D; Schott, Jonathan M; Alexander, Daniel C

2017-01-01

Model-based investigations of transneuronal spreading mechanisms in neurodegenerative diseases relate the pattern of pathology severity to the brain's connectivity matrix, which reveals information about how pathology propagates through the connectivity network. Such network models typically use networks based on functional or structural connectivity in young and healthy individuals, and only end-stage patterns of pathology, thereby ignoring/excluding the effects of normal aging and disease progression. Here, we examine the sequence of changes in the elderly brain's anatomical connectivity over the course of a neurodegenerative disease. We do this in a data-driven manner that is not dependent upon clinical disease stage, by using event-based disease progression modeling. Using data from the Alzheimer's Disease Neuroimaging Initiative dataset, we sequence the progressive decline of anatomical connectivity, as quantified by graph-theory metrics, in the Alzheimer's disease brain. Ours is the first single model to contribute to understanding all three of the nature, the location, and the sequence of changes to anatomical connectivity in the human brain due to Alzheimer's disease. Our experimental results reveal new insights into Alzheimer's disease: that degeneration of anatomical connectivity in the brain may be a viable, even early, biomarker and should be considered when studying such neurodegenerative diseases.

Translations of Selected Articles on Political and Sociological Subjects from Chinese Communist Periodicals.

DTIC Science & Technology

1960-08-10

Paper Tigers" 1? 3. Study Chairman Mao’s Correct Attitude toward New Things 31 ij.. Culture and Art Must Strive Toward 1960!s Continued Leap...we only entertain >eaceful intentions toward it and have no other ülan.»5 123-124. 121—122. - ^ - "* w "" Moreover, on nie basia of the theory...victory of th new era in human histo socialism has already this era of ours, this transition can a out. He observed that this and that for.’! of i

Designing Learning Spaces for Interprofessional Education in the Anatomical Sciences

ERIC Educational Resources Information Center

Cleveland, Benjamin; Kvan, Thomas

2015-01-01

This article explores connections between interprofessional education (IPE) models and the design of learning spaces for undergraduate and graduate education in the anatomical sciences and other professional preparation. The authors argue that for IPE models to be successful and sustained they must be embodied in the environment in which…

Bond Graph Model of Cerebral Circulation: Toward Clinically Feasible Systemic Blood Flow Simulations

PubMed Central

Safaei, Soroush; Blanco, Pablo J.; Müller, Lucas O.; Hellevik, Leif R.; Hunter, Peter J.

2018-01-01

We propose a detailed CellML model of the human cerebral circulation that runs faster than real time on a desktop computer and is designed for use in clinical settings when the speed of response is important. A lumped parameter mathematical model, which is based on a one-dimensional formulation of the flow of an incompressible fluid in distensible vessels, is constructed using a bond graph formulation to ensure mass conservation and energy conservation. The model includes arterial vessels with geometric and anatomical data based on the ADAN circulation model. The peripheral beds are represented by lumped parameter compartments. We compare the hemodynamics predicted by the bond graph formulation of the cerebral circulation with that given by a classical one-dimensional Navier-Stokes model working on top of the whole-body ADAN model. Outputs from the bond graph model, including the pressure and flow signatures and blood volumes, are compared with physiological data. PMID:29551979

Lung lobe modeling and segmentation with individualized surface meshes

NASA Astrophysics Data System (ADS)

Blaffert, Thomas; Barschdorf, Hans; von Berg, Jens; Dries, Sebastian; Franz, Astrid; Klinder, Tobias; Lorenz, Cristian; Renisch, Steffen; Wiemker, Rafael

2008-03-01

An automated segmentation of lung lobes in thoracic CT images is of interest for various diagnostic purposes like the quantification of emphysema or the localization of tumors within the lung. Although the separating lung fissures are visible in modern multi-slice CT-scanners, their contrast in the CT-image often does not separate the lobes completely. This makes it impossible to build a reliable segmentation algorithm without additional information. Our approach uses general anatomical knowledge represented in a geometrical mesh model to construct a robust lobe segmentation, which even gives reasonable estimates of lobe volumes if fissures are not visible at all. The paper describes the generation of the lung model mesh including lobes by an average volume model, its adaptation to individual patient data using a special fissure feature image, and a performance evaluation over a test data set showing an average segmentation accuracy of 1 to 3 mm.

[Biomechanical modeling of pelvic organ mobility: towards personalized medicine].

PubMed

Cosson, Michel; Rubod, Chrystèle; Vallet, Alexandra; Witz, Jean-François; Brieu, Mathias

2011-11-01

Female pelvic mobility is crucial for urinary, bowel and sexual function and for vaginal delivery. This mobility is ensured by a complex organ suspension system composed of ligaments, fascia and muscles. Impaired pelvic mobility affects one in three women of all ages and can be incapacitating. Surgical management has a high failure rate, largely owing to poor knowledge of the organ support system, including the barely discernible ligamentous system. We propose a 3D digital model of the pelvic cavity based on MRI images and quantitative tools, designed to locate the pelvic ligaments. We thus obtain a coherent anatomical and functional model which can be used to analyze pelvic pathophysiology. This work represents a first step towards creating a tool for localizing and characterizing the source of pelvic imbalance. We examine possible future applications of this model, in terms of personalized therapy and prevention.

Evaluation by Medical Students of the Educational Value of Multi-Material and Multi-Colored Three-Dimensional Printed Models of the Upper Limb for Anatomical Education

ERIC Educational Resources Information Center

Mogali, Sreenivasulu Reddy; Yeong, Wai Yee; Tan, Heang Kuan Joel; Tan, Gerald Jit Shen; Abrahams, Peter H.; Zary, Nabil; Low-Beer, Naomi; Ferenczi, Michael Alan

2018-01-01

For centuries, cadaveric material has been the cornerstone of anatomical education. For reasons of changes in curriculum emphasis, cost, availability, expertise, and ethical concerns, several medical schools have replaced wet cadaveric specimens with plastinated prosections, plastic models, imaging, and digital models. Discussions about the…

Explorable Three-Dimensional Digital Model of the Female Pelvis, Pelvic Contents, and Perineum for Anatomical Education

ERIC Educational Resources Information Center

Sergovich, Aimee; Johnson, Marjorie; Wilson, Timothy D.

2010-01-01

The anatomy of the pelvis is complex, multilayered, and its three-dimensional organization is conceptually difficult for students to grasp. The aim of this project was to create an explorable and projectable stereoscopic, three-dimensional (3D) model of the female pelvis and pelvic contents for anatomical education. The model was created using…

Hybrid computational phantoms of the 15-year male and female adolescent: Applications to CT organ dosimetry for patients of variable morphometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Choonsik; Lodwick, Daniel; Williams, Jonathan L.

Currently, two classes of the computational phantoms have been developed for dosimetry calculation: (1) stylized (or mathematical) and (2) voxel (or tomographic) phantoms describing human anatomy through mathematical surface equations and three-dimensional labeled voxel matrices, respectively. Mathematical surface equations in stylized phantoms provide flexibility in phantom design and alteration, but the resulting anatomical description is, in many cases, not very realistic. Voxel phantoms display far better anatomical realism, but they are limited in terms of their ability to alter organ shape, position, and depth, as well as body posture. A new class of computational phantoms - called hybrid phantoms -more » takes advantage of the best features of stylized and voxel phantoms - flexibility and anatomical realism, respectively. In the current study, hybrid computational phantoms representing reference 15-year male and female body anatomy and anthropometry are presented. For the male phantom, organ contours were extracted from the University of Florida (UF) 14-year series B male voxel phantom, while for the female phantom, original computed tomography (CT) data from two 14-year female patients were used. Polygon mesh models for the major organs and tissues were reconstructed for nonuniform rational B-spline (NURBS) surface modeling. The resulting NURBS/polygon mesh models representing body contour and internal anatomy were matched to anthropometric data and reference organ mass data provided by the Centers for Disease Control and Prevention (CDC) and the International Commission on Radiation Protection (ICRP), respectively. Finally, two hybrid 15-year male and female phantoms were completed where a total of eight anthropometric data categories were matched to standard values within 4% and organ masses matched to ICRP data within 1% with the exception of total skin. To highlight the flexibility of the hybrid phantoms, 10th and 90th weight percentile 15-year male and female phantoms were further developed from the 50th percentile phantoms through adjustments in the body contour to match the total body masses given in CDC pediatric growth curves. The resulting six NURBS phantoms, male and female phantoms representing their 10th, 50th, and 90th weight percentiles, were used to investigate the influence of body fat distributions on internal organ doses following CT imaging. The phantoms were exposed to multislice chest and abdomen helical CT scans, and in-field organ absorbed doses were calculated. The results demonstrated that the use of traditional stylized phantoms yielded organ dose estimates that deviate from those given by the UF reference hybrid phantoms by up to a factor of 2. The study also showed that use of reference, or 50th percentile, phantoms to assess organ doses in underweight 15-year-old children would not lead to significant organ dose errors (typically less than 10%). However, more significant errors were noted (up to {approx}30%) when reference phantoms are used to represent overweight children in CT imaging dosimetry. These errors are expected to only further increase as one considers CT organ doses in overweight and obese individuals of the adult patient population, thus emphasizing the advantages of patient-sculptable phantom technology.« less

A theoretical analysis of anatomical and functional intestinal slow wave re-entry.

PubMed

Du, Peng; O'Grady, Gregory; Cheng, Leo K

2017-07-21

Intestinal bioelectrical slow waves are a key regulator of intestinal motility. Peripheral pacemakers, ectopic initiations and sustained periods of re-entrant activities have all been experimentally observed to be important factors in setting the frequency of intestinal slow waves, but the tissue-level mechanisms underpinning these activities are unclear. This theoretical analysis aimed to define the initiation, maintenance, and termination criteria of two classes of intestinal re-entrant activities: anatomical re-entry and functional re-entry. Anatomical re-entry was modeled in a three-dimensional (3D) cylindrical model, and functional rotor was modeled in a 2D rectangle model. A single-pulse stimulus was used to invoke an anatomical re-entry and a prolonged refractory block was used to invoke the rotor. In both cases, the simulated re-entrant activities operated at frequencies above the baseline entrainment frequency. The anatomical re-entry simulation results demonstrated that a temporary functional refractory block would be required to initiate the re-entrant activity in a single direction around the cylindrical model. The rotor could be terminated by a single-pulse stimulus delivered around the core of the rotor. In conclusion, the simulation results provide the following new insights into the mechanisms of intestinal re-entry: (i) anatomical re-entry is only maintained within a specific range of velocities, outside of which the re-entrant activities become either an ectopic activity or simultaneous activations of the intestinal wall; (ii) a maintained rotor entrained slow waves faster in the antegrade direction than in the retrograde direction. Simulations are shown to be a valuable tool for achieving novel insights into the mechanisms of intestinal slow wave dysrhythmia. Copyright © 2017 Elsevier Ltd. All rights reserved.

COMICS: Cartoon Visualization of Omics Data in Spatial Context Using Anatomical Ontologies

PubMed Central

2017-01-01

COMICS is an interactive and open-access web platform for integration and visualization of molecular expression data in anatomograms of zebrafish, carp, and mouse model systems. Anatomical ontologies are used to map omics data across experiments and between an experiment and a particular visualization in a data-dependent manner. COMICS is built on top of several existing resources. Zebrafish and mouse anatomical ontologies with their controlled vocabulary (CV) and defined hierarchy are used with the ontoCAT R package to aggregate data for comparison and visualization. Libraries from the QGIS geographical information system are used with the R packages “maps” and “maptools” to visualize and interact with molecular expression data in anatomical drawings of the model systems. COMICS allows users to upload their own data from omics experiments, using any gene or protein nomenclature they wish, as long as CV terms are used to define anatomical regions or developmental stages. Common nomenclatures such as the ZFIN gene names and UniProt accessions are provided additional support. COMICS can be used to generate publication-quality visualizations of gene and protein expression across experiments. Unlike previous tools that have used anatomical ontologies to interpret imaging data in several animal models, including zebrafish, COMICS is designed to take spatially resolved data generated by dissection or fractionation and display this data in visually clear anatomical representations rather than large data tables. COMICS is optimized for ease-of-use, with a minimalistic web interface and automatic selection of the appropriate visual representation depending on the input data. PMID:29083911

COMICS: Cartoon Visualization of Omics Data in Spatial Context Using Anatomical Ontologies.

PubMed

Travin, Dmitrii; Popov, Iaroslav; Guler, Arzu Tugce; Medvedev, Dmitry; van der Plas-Duivesteijn, Suzanne; Varela, Monica; Kolder, Iris C R M; Meijer, Annemarie H; Spaink, Herman P; Palmblad, Magnus

2018-01-05

COMICS is an interactive and open-access web platform for integration and visualization of molecular expression data in anatomograms of zebrafish, carp, and mouse model systems. Anatomical ontologies are used to map omics data across experiments and between an experiment and a particular visualization in a data-dependent manner. COMICS is built on top of several existing resources. Zebrafish and mouse anatomical ontologies with their controlled vocabulary (CV) and defined hierarchy are used with the ontoCAT R package to aggregate data for comparison and visualization. Libraries from the QGIS geographical information system are used with the R packages "maps" and "maptools" to visualize and interact with molecular expression data in anatomical drawings of the model systems. COMICS allows users to upload their own data from omics experiments, using any gene or protein nomenclature they wish, as long as CV terms are used to define anatomical regions or developmental stages. Common nomenclatures such as the ZFIN gene names and UniProt accessions are provided additional support. COMICS can be used to generate publication-quality visualizations of gene and protein expression across experiments. Unlike previous tools that have used anatomical ontologies to interpret imaging data in several animal models, including zebrafish, COMICS is designed to take spatially resolved data generated by dissection or fractionation and display this data in visually clear anatomical representations rather than large data tables. COMICS is optimized for ease-of-use, with a minimalistic web interface and automatic selection of the appropriate visual representation depending on the input data.

Sharing and reusing cardiovascular anatomical models over the Web: a step towards the implementation of the virtual physiological human project.

PubMed

Gianni, Daniele; McKeever, Steve; Yu, Tommy; Britten, Randall; Delingette, Hervé; Frangi, Alejandro; Hunter, Peter; Smith, Nicolas

2010-06-28

Sharing and reusing anatomical models over the Web offers a significant opportunity to progress the investigation of cardiovascular diseases. However, the current sharing methodology suffers from the limitations of static model delivery (i.e. embedding static links to the models within Web pages) and of a disaggregated view of the model metadata produced by publications and cardiac simulations in isolation. In the context of euHeart--a research project targeting the description and representation of cardiovascular models for disease diagnosis and treatment purposes--we aim to overcome the above limitations with the introduction of euHeartDB, a Web-enabled database for anatomical models of the heart. The database implements a dynamic sharing methodology by managing data access and by tracing all applications. In addition to this, euHeartDB establishes a knowledge link with the physiome model repository by linking geometries to CellML models embedded in the simulation of cardiac behaviour. Furthermore, euHeartDB uses the exFormat--a preliminary version of the interoperable FieldML data format--to effectively promote reuse of anatomical models, and currently incorporates Continuum Mechanics, Image Analysis, Signal Processing and System Identification Graphical User Interface (CMGUI), a rendering engine, to provide three-dimensional graphical views of the models populating the database. Currently, euHeartDB stores 11 cardiac geometries developed within the euHeart project consortium.

Morphological Constraints on Cerebellar Granule Cell Combinatorial Diversity.

PubMed

Gilmer, Jesse I; Person, Abigail L

2017-12-13

Combinatorial expansion by the cerebellar granule cell layer (GCL) is fundamental to theories of cerebellar contributions to motor control and learning. Granule cells (GrCs) sample approximately four mossy fiber inputs and are thought to form a combinatorial code useful for pattern separation and learning. We constructed a spatially realistic model of the cerebellar GCL and examined how GCL architecture contributes to GrC combinatorial diversity. We found that GrC combinatorial diversity saturates quickly as mossy fiber input diversity increases, and that this saturation is in part a consequence of short dendrites, which limit access to diverse inputs and favor dense sampling of local inputs. This local sampling also produced GrCs that were combinatorially redundant, even when input diversity was extremely high. In addition, we found that mossy fiber clustering, which is a common anatomical pattern, also led to increased redundancy of GrC input combinations. We related this redundancy to hypothesized roles of temporal expansion of GrC information encoding in service of learned timing, and we show that GCL architecture produces GrC populations that support both temporal and combinatorial expansion. Finally, we used novel anatomical measurements from mice of either sex to inform modeling of sparse and filopodia-bearing mossy fibers, finding that these circuit features uniquely contribute to enhancing GrC diversification and redundancy. Our results complement information theoretic studies of granule layer structure and provide insight into the contributions of granule layer anatomical features to afferent mixing. SIGNIFICANCE STATEMENT Cerebellar granule cells are among the simplest neurons, with tiny somata and, on average, just four dendrites. These characteristics, along with their dense organization, inspired influential theoretical work on the granule cell layer as a combinatorial expander, where each granule cell represents a unique combination of inputs. Despite the centrality of these theories to cerebellar physiology, the degree of expansion supported by anatomically realistic patterns of inputs is unknown. Using modeling and anatomy, we show that realistic input patterns constrain combinatorial diversity by producing redundant combinations, which nevertheless could support temporal diversification of like combinations, suitable for learned timing. Our study suggests a neural substrate for producing high levels of both combinatorial and temporal diversity in the granule cell layer. Copyright © 2017 the authors 0270-6474/17/3712153-14$15.00/0.

Development of a new generation of high-resolution anatomical models for medical device evaluation: the Virtual Population 3.0

NASA Astrophysics Data System (ADS)

Gosselin, Marie-Christine; Neufeld, Esra; Moser, Heidi; Huber, Eveline; Farcito, Silvia; Gerber, Livia; Jedensjö, Maria; Hilber, Isabel; Di Gennaro, Fabienne; Lloyd, Bryn; Cherubini, Emilio; Szczerba, Dominik; Kainz, Wolfgang; Kuster, Niels

2014-09-01

The Virtual Family computational whole-body anatomical human models were originally developed for electromagnetic (EM) exposure evaluations, in particular to study how absorption of radiofrequency radiation from external sources depends on anatomy. However, the models immediately garnered much broader interest and are now applied by over 300 research groups, many from medical applications research fields. In a first step, the Virtual Family was expanded to the Virtual Population to provide considerably broader population coverage with the inclusion of models of both sexes ranging in age from 5 to 84 years old. Although these models have proven to be invaluable for EM dosimetry, it became evident that significantly enhanced models are needed for reliable effectiveness and safety evaluations of diagnostic and therapeutic applications, including medical implants safety. This paper describes the research and development performed to obtain anatomical models that meet the requirements necessary for medical implant safety assessment applications. These include implementation of quality control procedures, re-segmentation at higher resolution, more-consistent tissue assignments, enhanced surface processing and numerous anatomical refinements. Several tools were developed to enhance the functionality of the models, including discretization tools, posing tools to expand the posture space covered, and multiple morphing tools, e.g., to develop pathological models or variations of existing ones. A comprehensive tissue properties database was compiled to complement the library of models. The results are a set of anatomically independent, accurate, and detailed models with smooth, yet feature-rich and topologically conforming surfaces. The models are therefore suited for the creation of unstructured meshes, and the possible applications of the models are extended to a wider range of solvers and physics. The impact of these improvements is shown for the MRI exposure of an adult woman with an orthopedic spinal implant. Future developments include the functionalization of the models for specific physical and physiological modeling tasks.

Computational Modeling of Inflammation and Wound Healing

PubMed Central

Ziraldo, Cordelia; Mi, Qi; An, Gary; Vodovotz, Yoram

2013-01-01

Objective Inflammation is both central to proper wound healing and a key driver of chronic tissue injury via a positive-feedback loop incited by incidental cell damage. We seek to derive actionable insights into the role of inflammation in wound healing in order to improve outcomes for individual patients. Approach To date, dynamic computational models have been used to study the time evolution of inflammation in wound healing. Emerging clinical data on histo-pathological and macroscopic images of evolving wounds, as well as noninvasive measures of blood flow, suggested the need for tissue-realistic, agent-based, and hybrid mechanistic computational simulations of inflammation and wound healing. Innovation We developed a computational modeling system, Simple Platform for Agent-based Representation of Knowledge, to facilitate the construction of tissue-realistic models. Results A hybrid equation–agent-based model (ABM) of pressure ulcer formation in both spinal cord-injured and -uninjured patients was used to identify control points that reduce stress caused by tissue ischemia/reperfusion. An ABM of arterial restenosis revealed new dynamics of cell migration during neointimal hyperplasia that match histological features, but contradict the currently prevailing mechanistic hypothesis. ABMs of vocal fold inflammation were used to predict inflammatory trajectories in individuals, possibly allowing for personalized treatment. Conclusions The intertwined inflammatory and wound healing responses can be modeled computationally to make predictions in individuals, simulate therapies, and gain mechanistic insights. PMID:24527362

The contribution of the human posterior parietal cortex to episodic memory.

PubMed

Sestieri, Carlo; Shulman, Gordon L; Corbetta, Maurizio

2017-02-17

The posterior parietal cortex (PPC) is traditionally associated with attention, perceptual decision making and sensorimotor transformations, but more recent human neuroimaging studies support an additional role in episodic memory retrieval. In this Opinion article, we present a functional-anatomical model of the involvement of the PPC in memory retrieval. Parietal regions involved in perceptual attention and episodic memory are largely segregated and often show a push-pull relationship, potentially mediated by prefrontal regions. Moreover, different PPC regions carry out specific functions during retrieval - for example, representing retrieved information, recoding this information based on task demands, or accumulating evidence for memory decisions.

The contribution of the human posterior parietal cortex to episodic memory

PubMed Central

Sestieri, Carlo; Shulman, Gordon L.; Corbetta, Maurizio

2017-01-01

The posterior parietal cortex (PPC) is traditionally associated with attention, perceptual decision making and sensorimotor transformations, but more recent human neuroimaging studies support an additional role in episodic memory retrieval. In this Opinion article, we present a functional–anatomical model of the involvement of the PPC in memory retrieval. Parietal regions involved in perceptual attention and episodic memory are largely segregated and often show a push–pull relationship, potentially mediated by prefrontal regions. Moreover, different PPC regions carry out specific functions during retrieval — for example, representing retrieved information, recoding this information based on task demands, or accumulating evidence for memory decisions. PMID:28209980

Musculoskeletal Simulation Model Generation from MRI Data Sets and Motion Capture Data

NASA Astrophysics Data System (ADS)

Schmid, Jérôme; Sandholm, Anders; Chung, François; Thalmann, Daniel; Delingette, Hervé; Magnenat-Thalmann, Nadia

Today computer models and computer simulations of the musculoskeletal system are widely used to study the mechanisms behind human gait and its disorders. The common way of creating musculoskeletal models is to use a generic musculoskeletal model based on data derived from anatomical and biomechanical studies of cadaverous specimens. To adapt this generic model to a specific subject, the usual approach is to scale it. This scaling has been reported to introduce several errors because it does not always account for subject-specific anatomical differences. As a result, a novel semi-automatic workflow is proposed that creates subject-specific musculoskeletal models from magnetic resonance imaging (MRI) data sets and motion capture data. Based on subject-specific medical data and a model-based automatic segmentation approach, an accurate modeling of the anatomy can be produced while avoiding the scaling operation. This anatomical model coupled with motion capture data, joint kinematics information, and muscle-tendon actuators is finally used to create a subject-specific musculoskeletal model.

Evidence for a genetic discontinuity between Neandertals and 24,000-year-old anatomically modern Europeans.

PubMed

Caramelli, David; Lalueza-Fox, Carles; Vernesi, Cristiano; Lari, Martina; Casoli, Antonella; Mallegni, Francesco; Chiarelli, Brunetto; Dupanloup, Isabelle; Bertranpetit, Jaume; Barbujani, Guido; Bertorelle, Giorgio

2003-05-27

During the late Pleistocene, early anatomically modern humans coexisted in Europe with the anatomically archaic Neandertals for some thousand years. Under the recent variants of the multiregional model of human evolution, modern and archaic forms were different but related populations within a single evolving species, and both have contributed to the gene pool of current humans. Conversely, the Out-of-Africa model considers the transition between Neandertals and anatomically modern humans as the result of a demographic replacement, and hence it predicts a genetic discontinuity between them. Following the most stringent current standards for validation of ancient DNA sequences, we typed the mtDNA hypervariable region I of two anatomically modern Homo sapiens sapiens individuals of the Cro-Magnon type dated at about 23 and 25 thousand years ago. Here we show that the mtDNAs of these individuals fall well within the range of variation of today's humans, but differ sharply from the available sequences of the chronologically closer Neandertals. This discontinuity is difficult to reconcile with the hypothesis that both Neandertals and early anatomically modern humans contributed to the current European gene pool.

A Feature-based Developmental Model of the Infant Brain in Structural MRI

PubMed Central

Toews, Matthew; Wells, William M.; Zöllei, Lilla

2014-01-01

In this paper, anatomical development is modeled as a collection of distinctive image patterns localized in space and time. A Bayesian posterior probability is defined over a random variable of subject age, conditioned on data in the form of scale-invariant image features. The model is automatically learned from a large set of images exhibiting significant variation, used to discover anatomical structure related to age and development, and fit to new images to predict age. The model is applied to a set of 230 infant structural MRIs of 92 subjects acquired at multiple sites over an age range of 8-590 days. Experiments demonstrate that the model can be used to identify age-related anatomical structure, and to predict the age of new subjects with an average error of 72 days. PMID:23286050

The history of Latin terminology of human skeletal muscles (from Vesalius to the present).

PubMed

Musil, Vladimir; Suchomel, Zdenek; Malinova, Petra; Stingl, Josef; Vlcek, Martin; Vacha, Marek

2015-01-01

The aim of this literary search was to chart the etymology of 32 selected human skeletal muscles, representative of all body regions. In researching this study, analysis of 15 influential Latin and German anatomical textbooks, dating from the sixteenth to the nineteenth century, was undertaken, as well as reference to four versions of the official Latin anatomical terminologies. Particular emphasis has been placed on the historical development of muscular nomenclature, and the subsequent division of these data into groups, defined by similarities in the evolution of their names into the modern form. The first group represents examples of muscles whose names have not changed since their introduction by Vesalius (1543). The second group comprises muscles which earned their definitive names during the seventeenth and eighteenth century. The third group is defined by acceptance into common anatomical vernacular by the late nineteenth century, including those outlined in the first official Latin terminology (B.N.A.) of 1895. The final group is reserved for six extra-ocular muscles with a particularly poetic history, favoured and popularised by the anatomical giants of late Renaissance and 1,700 s. As this study will demonstrate, it is evident that up until introduction of the B.N.A. there was an extremely liberal approach to naming muscles, deserving great respect in the retrospective terminological studies if complete and relevant results are to be achieved. Without this knowledge of the vernacular of the ages past, modern researchers can find themselves 'reinventing the wheel' in looking for their answers.

[Multi-center study of the Jenaer model of the temporal bone].

PubMed

Schneider, G; Müller, A

2004-06-01

Preparing exercises at the temporal bone are a prerequisite for the knowledge of the anatomical special features of this region and for learning the fundamentals of the tympanic cavity surgery. Since however fewer human temporal bones are available, the search for back-up models already took place in the last years. Based on the experiences of the handling and visualization of CT data for the 3D-implant construction in the ent department Jena a temporal bone model was developed. The model was sent away to surgeons of different training. On the basis of identification of anatomical structures and evaluation of general parameters by means of a point system the model was evaluated. The Jenaer temporal bone model is suitable as entrance into the preparing exercises. The anatomical structures are good to identify for the beginner. The handling with drill and chisel can be learned.

A Computational Model Quantifies the Effect of Anatomical Variability on Velopharyngeal Function

ERIC Educational Resources Information Center

Inouye, Joshua M.; Perry, Jamie L.; Lin, Kant Y.; Blemker, Silvia S.

2015-01-01

Purpose: This study predicted the effects of velopharyngeal (VP) anatomical parameters on VP function to provide a greater understanding of speech mechanics and aid in the treatment of speech disorders. Method: We created a computational model of the VP mechanism using dimensions obtained from magnetic resonance imaging measurements of 10 healthy…

Uncovered secret of a Vasseur-Tramond wax model.

PubMed

Pastor, J F; Gutiérrez, B; Montes, J M; Ballestriero, R

2016-01-01

The technique of anatomical wax modelling reached its heyday in Italy during the 18th century, through a fruitful collaboration between sculptors and anatomists. It soon spread to other countries, and prestigious schools were created in England, France, Spain and Austria. Paris subsequently replaced Italy as the major centre of manufacture, and anatomical waxes were created there from the mid-19th century in workshops such as that of Vasseur-Tramond. This workshop began to sell waxes to European Faculties of Medicine and Schools of Surgery around 1880. Little is known of the technique employed in the creation of such artefacts as this was deemed a professional secret. To gain some insight into the methods of construction, we have studied a Vasseur-Tramond wax model in the Valladolid University Anatomy Museum, Spain, by means of multi-slice computerised tomography and X-ray analysis by means of environmental scanning electron microscopy. Scanning electron microscopy was used to examine the hair. These results have revealed some of the methods used to make these anatomical models and the materials employed. © 2015 Anatomical Society.

WE-G-207-06: 3D Fluoroscopic Image Generation From Patient-Specific 4DCBCT-Based Motion Models Derived From Physical Phantom and Clinical Patient Images

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dhou, S; Cai, W; Hurwitz, M

2015-06-15

Purpose: Respiratory-correlated cone-beam CT (4DCBCT) images acquired immediately prior to treatment have the potential to represent patient motion patterns and anatomy during treatment, including both intra- and inter-fractional changes. We develop a method to generate patient-specific motion models based on 4DCBCT images acquired with existing clinical equipment and used to generate time varying volumetric images (3D fluoroscopic images) representing motion during treatment delivery. Methods: Motion models are derived by deformably registering each 4DCBCT phase to a reference phase, and performing principal component analysis (PCA) on the resulting displacement vector fields. 3D fluoroscopic images are estimated by optimizing the resulting PCAmore » coefficients iteratively through comparison of the cone-beam projections simulating kV treatment imaging and digitally reconstructed radiographs generated from the motion model. Patient and physical phantom datasets are used to evaluate the method in terms of tumor localization error compared to manually defined ground truth positions. Results: 4DCBCT-based motion models were derived and used to generate 3D fluoroscopic images at treatment time. For the patient datasets, the average tumor localization error and the 95th percentile were 1.57 and 3.13 respectively in subsets of four patient datasets. For the physical phantom datasets, the average tumor localization error and the 95th percentile were 1.14 and 2.78 respectively in two datasets. 4DCBCT motion models are shown to perform well in the context of generating 3D fluoroscopic images due to their ability to reproduce anatomical changes at treatment time. Conclusion: This study showed the feasibility of deriving 4DCBCT-based motion models and using them to generate 3D fluoroscopic images at treatment time in real clinical settings. 4DCBCT-based motion models were found to account for the 3D non-rigid motion of the patient anatomy during treatment and have the potential to localize tumor and other patient anatomical structures at treatment time even when inter-fractional changes occur. This project was supported, in part, through a Master Research Agreement with Varian Medical Systems, Inc., Palo Alto, CA. The project was also supported, in part, by Award Number R21CA156068 from the National Cancer Institute.« less

A time dependent anatomically detailed model of cardiac conduction

NASA Technical Reports Server (NTRS)

Saxberg, B. E.; Grumbach, M. P.; Cohen, R. J.

1985-01-01

In order to understand the determinants of transitions in cardiac electrical activity from normal patterns to dysrhythmias such as ventricular fibrillation, we are constructing an anatomically and physiologically detailed finite element simulation of myocardial electrical propagation. A healthy human heart embedded in paraffin was sectioned to provide a detailed anatomical substrate for model calculations. The simulation of propagation includes anisotropy in conduction velocity due to fiber orientation as well as gradients in conduction velocities, absolute and relative refractory periods, action potential duration and electrotonic influence of nearest neighbors. The model also includes changes in the behaviour of myocardial tissue as a function of the past local activity. With this model, we can examine the significance of fiber orientation and time dependence of local propagation parameters on dysrhythmogenesis.

AnatomicalTerms.info: heading for an online solution to the anatomical synonym problem hurdles in data-reuse from the Terminologia Anatomica and the foundational model of anatomy and potentials for future development.

PubMed

Gobée, O Paul; Jansma, Daniël; DeRuiter, Marco C

2011-10-01

The many synonyms for anatomical structures confuse medical students and complicate medical communication. Easily accessible translations would alleviate this problem. None of the presently available resources-Terminologia Anatomica (TA), digital terminologies such as the Foundational Model of Anatomy (FMA), and websites-are fully satisfactory to this aim. Internet technologies offer new possibilities to solve the problem. Several authors have called for an online TA. An online translation resource should be easily accessible, user-friendly, comprehensive, expandable, and its quality determinable. As first step towards this goal, we built a translation website that we named www.AnatomicalTerms.info, based on the database of the FMA. It translates between English, Latin, eponyms, and to a lesser extent other languages, and presently contains over 31,000 terms for 7,250 structures, covering 95% of TA. In addition, it automatically presents searches for images, documents and anatomical variations regarding the sought structure. Several terminological and conceptual issues were encountered in transferring data from TA and FMA into AnatomicalTerms.info, resultant from these resources' different set-ups (paper versus digital) and targets (machine versus human-user). To the best of our knowledge, AnatomicalTerms.info is unique in its combination of user-friendliness and comprehensiveness. As next step, wiki-like expandability will be added to enable open contribution of clinical synonyms and terms in different languages. Specific quality measures will be taken to strike a balance between open contribution and quality assurance. AnatomicalTerms.info's mechanism that "translates" terms to structures furthermore may enhance targeted searching by linking images, descriptions, and other anatomical resources to the structures. Copyright © 2011 Wiley-Liss, Inc.

Crystal Structures of the Histo-Aspartic Protease (HAP) from Plasmodium falciparum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhaumik, Prasenjit; Xiao, Huogen; Parr, Charity L.

The structures of recombinant histo-aspartic protease (HAP) from malaria-causing parasite Plasmodium falciparum as apoenzyme and in complex with two inhibitors, pepstatin A and KNI-10006, were solved at 2.5-, 3.3-, and 3.05-{angstrom} resolutions, respectively. In the apoenzyme crystals, HAP forms a tight dimer not seen previously in any aspartic protease. The interactions between the monomers affect the conformation of two flexible loops, the functionally important 'flap' (residues 70-83) and its structural equivalent in the C-terminal domain (residues 238-245), as well as the orientation of helix 225-235. The flap is found in an open conformation in the apoenzyme. Unexpectedly, the active sitemore » of the apoenzyme contains a zinc ion tightly bound to His32 and Asp215 from one monomer and to Glu278A from the other monomer, with the coordination of Zn resembling that seen in metalloproteases. The flap is closed in the structure of the pepstatin A complex, whereas it is open in the complex with KNI-10006. Although the binding mode of pepstatin A is significantly different from that in other pepsin-like aspartic proteases, its location in the active site makes unlikely the previously proposed hypothesis that HAP is a serine protease. The binding mode of KNI-10006 is unusual compared with the binding of other inhibitors from the KNI series to aspartic proteases. The novel features of the HAP active site could facilitate design of specific inhibitors used in the development of antimalarial drugs.« less

Inferring anatomical therapeutic chemical (ATC) class of drugs using shortest path and random walk with restart algorithms.

PubMed

Chen, Lei; Liu, Tao; Zhao, Xian

2018-06-01

The anatomical therapeutic chemical (ATC) classification system is a widely accepted drug classification scheme. This system comprises five levels and includes several classes in each level. Drugs are classified into classes according to their therapeutic effects and characteristics. The first level includes 14 main classes. In this study, we proposed two network-based models to infer novel potential chemicals deemed to belong in the first level of ATC classification. To build these models, two large chemical networks were constructed using the chemical-chemical interaction information retrieved from the Search Tool for Interactions of Chemicals (STITCH). Two classic network algorithms, shortest path (SP) and random walk with restart (RWR) algorithms, were executed on the corresponding network to mine novel chemicals for each ATC class using the validated drugs in a class as seed nodes. Then, the obtained chemicals yielded by these two algorithms were further evaluated by a permutation test and an association test. The former can exclude chemicals produced by the structure of the network, i.e., false positive discoveries. By contrast, the latter identifies the most important chemicals that have strong associations with the ATC class. Comparisons indicated that the two models can provide quite dissimilar results, suggesting that the results yielded by one model can be essential supplements for those obtained by the other model. In addition, several representative inferred chemicals were analyzed to confirm the reliability of the results generated by the two models. This article is part of a Special Issue entitled: Accelerating Precision Medicine through Genetic and Genomic Big Data Analysis edited by Yudong Cai & Tao Huang. Copyright © 2017 Elsevier B.V. All rights reserved.

Assessment of vinyl polysiloxane as an innovative injection material for the anatomical study of vasculature.

PubMed

Dargaud, Jacques; Chalvet, Laurane; Del Corso, Marco; Cerboni, Elsa; Feugier, Patrick; Mertens, Patrick; Simon, Emile

2016-04-01

There are numerous injection materials for the study of vasculature in anatomical specimens, each having its own advantages and disadvantages. Latex and resins are the most widely used injection materials but need several days to set. The development of new materials taking shorter time to polymerize might be very useful to improve anatomic specimen study conditions. The aim of the present study was to evaluate vinyl polysiloxane (VPS), a silicon material widely used for dental impressions with the advantage to set very rapidly, as an injection material. We assessed the preparation, use, diffusion and setting time of the product in different anatomical regions (central nervous system, external carotid/jugular, lower limb) to observe its behavior in variably sized vessels. Our results suggest that VPS might be of interest for the study of vessels in anatomical specimens. The main strengths of the product are represented by (1) simplicity of use, as it is a ready-to-use material, (2) very rapid polymerization, (3) availability in a range of viscosities making easier the exploration of small vessels, (4) its better elasticity compared to resins, (5) and finally its availability in a range of colors making it a material of choice for vascular system dissections including those with very small caliber vessels.

DIAGNOSIS OF ENDOCRINE DISEASE: High-yield thyroid fine-needle aspiration cytology: an update focused on ancillary techniques improving its accuracy.

PubMed

Bongiovanni, M; Trimboli, P; Rossi, E D; Fadda, G; Nobile, A; Giovanella, L

2016-02-01

Thyroid fine-needle aspiration (FNA) cytology is a fast growing field. One of the most developing areas is represented by molecular tests applied to cytological material. Patients that could benefit the most from these tests are those that have been diagnosed as 'indeterminate' on FNA. They could be better stratified in terms of malignancy risk and thus oriented with more confidence to the appropriate management. Taking in to consideration the need to improve and keep high the yield of thyroid FNA, professionals from various fields (i.e. molecular biologists, endocrinologists, nuclear medicine physicians and radiologists) are refining and fine-tuning their diagnostic instruments. In particular, all these developments aim at increasing the negative predictive value of FNA to improve the selection of patients for diagnostic surgery. These advances involve terminology, the application of next-generation sequencing to thyroid FNA, the use of immunocyto- and histo-chemistry, the development of new sampling techniques and the increasing use of nuclear medicine as well as molecular imaging in the management of patients with a thyroid nodule. Herein, we review the recent advances in thyroid FNA cytology that could be of interest to the 'thyroid-care' community, with particular focus on the indeterminate diagnostic category. © 2016 European Society of Endocrinology.

Urine concentrating mechanism: impact of vascular and tubular architecture and a proposed descending limb urea-Na+ cotransporter

PubMed Central

Dantzler, William H.; Pannabecker, Thomas L.

2012-01-01

We extended a region-based mathematical model of the renal medulla of the rat kidney, previously developed by us, to represent new anatomic findings on the vascular architecture in the rat inner medulla (IM). In the outer medulla (OM), tubules and vessels are organized around tightly packed vascular bundles; in the IM, the organization is centered around collecting duct clusters. In particular, the model represents the separation of descending vasa recta from the descending limbs of loops of Henle, and the model represents a papillary segment of the descending thin limb that is water impermeable and highly urea permeable. Model results suggest that, despite the compartmentalization of IM blood flow, IM interstitial fluid composition is substantially more homogeneous compared with OM. We used the model to study medullary blood flow in antidiuresis and the effects of vascular countercurrent exchange. We also hypothesize that the terminal aquaporin-1 null segment of the long descending thin limbs may express a urea-Na+ or urea-Cl− cotransporter. As urea diffuses from the urea-rich papillary interstitium into the descending thin limb luminal fluid, NaCl is secreted via the cotransporter against its concentration gradient. That NaCl is then reabsorbed near the loop bend, raising the interstitial fluid osmolality and promoting water reabsorption from the IM collecting ducts. Indeed, the model predicts that the presence of the urea-Na+ or urea- Cl− cotransporter facilitates the cycling of NaCl within the IM and yields a loop-bend fluid composition consistent with experimental data. PMID:22088433

Urine concentrating mechanism: impact of vascular and tubular architecture and a proposed descending limb urea-Na+ cotransporter.

PubMed

Layton, Anita T; Dantzler, William H; Pannabecker, Thomas L

2012-03-01

We extended a region-based mathematical model of the renal medulla of the rat kidney, previously developed by us, to represent new anatomic findings on the vascular architecture in the rat inner medulla (IM). In the outer medulla (OM), tubules and vessels are organized around tightly packed vascular bundles; in the IM, the organization is centered around collecting duct clusters. In particular, the model represents the separation of descending vasa recta from the descending limbs of loops of Henle, and the model represents a papillary segment of the descending thin limb that is water impermeable and highly urea permeable. Model results suggest that, despite the compartmentalization of IM blood flow, IM interstitial fluid composition is substantially more homogeneous compared with OM. We used the model to study medullary blood flow in antidiuresis and the effects of vascular countercurrent exchange. We also hypothesize that the terminal aquaporin-1 null segment of the long descending thin limbs may express a urea-Na(+) or urea-Cl(-) cotransporter. As urea diffuses from the urea-rich papillary interstitium into the descending thin limb luminal fluid, NaCl is secreted via the cotransporter against its concentration gradient. That NaCl is then reabsorbed near the loop bend, raising the interstitial fluid osmolality and promoting water reabsorption from the IM collecting ducts. Indeed, the model predicts that the presence of the urea-Na(+) or urea- Cl(-) cotransporter facilitates the cycling of NaCl within the IM and yields a loop-bend fluid composition consistent with experimental data.

Specific absorbed fractions of electrons and photons for Rad-HUMAN phantom using Monte Carlo method

NASA Astrophysics Data System (ADS)

Wang, Wen; Cheng, Meng-Yun; Long, Peng-Cheng; Hu, Li-Qin

2015-07-01

The specific absorbed fractions (SAF) for self- and cross-irradiation are effective tools for the internal dose estimation of inhalation and ingestion intakes of radionuclides. A set of SAFs of photons and electrons were calculated using the Rad-HUMAN phantom, which is a computational voxel phantom of a Chinese adult female that was created using the color photographic image of the Chinese Visible Human (CVH) data set by the FDS Team. The model can represent most Chinese adult female anatomical characteristics and can be taken as an individual phantom to investigate the difference of internal dose with Caucasians. In this study, the emission of mono-energetic photons and electrons of 10 keV to 4 MeV energy were calculated using the Monte Carlo particle transport calculation code MCNP. Results were compared with the values from ICRP reference and ORNL models. The results showed that SAF from the Rad-HUMAN have similar trends but are larger than those from the other two models. The differences were due to the racial and anatomical differences in organ mass and inter-organ distance. The SAFs based on the Rad-HUMAN phantom provide an accurate and reliable data for internal radiation dose calculations for Chinese females. Supported by Strategic Priority Research Program of Chinese Academy of Sciences (XDA03040000), National Natural Science Foundation of China (910266004, 11305205, 11305203) and National Special Program for ITER (2014GB112001)

Chemotaxis in densely populated tissue determines germinal center anatomy and cell motility: a new paradigm for the development of complex tissues.

PubMed

Hawkins, Jared B; Jones, Mark T; Plassmann, Paul E; Thorley-Lawson, David A

2011-01-01

Germinal centers (GCs) are complex dynamic structures that form within lymph nodes as an essential process in the humoral immune response. They represent a paradigm for studying the regulation of cell movement in the development of complex anatomical structures. We have developed a simulation of a modified cyclic re-entry model of GC dynamics which successfully employs chemotaxis to recapitulate the anatomy of the primary follicle and the development of a mature GC, including correctly structured mantle, dark and light zones. We then show that correct single cell movement dynamics (including persistent random walk and inter-zonal crossing) arise from this simulation as purely emergent properties. The major insight of our study is that chemotaxis can only achieve this when constrained by the known biological properties that cells are incompressible, exist in a densely packed environment, and must therefore compete for space. It is this interplay of chemotaxis and competition for limited space that generates all the complex and biologically accurate behaviors described here. Thus, from a single simple mechanism that is well documented in the biological literature, we can explain both higher level structure and single cell movement behaviors. To our knowledge this is the first GC model that is able to recapitulate both correctly detailed anatomy and single cell movement. This mechanism may have wide application for modeling other biological systems where cells undergo complex patterns of movement to produce defined anatomical structures with sharp tissue boundaries.

The role of photorespiration during the evolution of C4 photosynthesis in the genus Flaveria.

PubMed

Mallmann, Julia; Heckmann, David; Bräutigam, Andrea; Lercher, Martin J; Weber, Andreas P M; Westhoff, Peter; Gowik, Udo

2014-06-16

C4 photosynthesis represents a most remarkable case of convergent evolution of a complex trait, which includes the reprogramming of the expression patterns of thousands of genes. Anatomical, physiological, and phylogenetic and analyses as well as computational modeling indicate that the establishment of a photorespiratory carbon pump (termed C2 photosynthesis) is a prerequisite for the evolution of C4. However, a mechanistic model explaining the tight connection between the evolution of C4 and C2 photosynthesis is currently lacking. Here we address this question through comparative transcriptomic and biochemical analyses of closely related C3, C3-C4, and C4 species, combined with Flux Balance Analysis constrained through a mechanistic model of carbon fixation. We show that C2 photosynthesis creates a misbalance in nitrogen metabolism between bundle sheath and mesophyll cells. Rebalancing nitrogen metabolism requires anaplerotic reactions that resemble at least parts of a basic C4 cycle. Our findings thus show how C2 photosynthesis represents a pre-adaptation for the C4 system, where the evolution of the C2 system establishes important C4 components as a side effect.

3D spine reconstruction of postoperative patients from multi-level manifold ensembles.

PubMed

Kadoury, Samuel; Labelle, Hubert; Parent, Stefan

2014-01-01

The quantitative assessment of surgical outcomes using personalized anatomical models is an essential task for the treatment of spinal deformities such as adolescent idiopathic scoliosis. However an accurate 3D reconstruction of the spine from postoperative X-ray images remains challenging due to presence of instrumentation (metallic rods and screws) occluding vertebrae on the spine. In this paper, we formulate the reconstruction problem as an optimization over a manifold of articulated spine shapes learned from pathological training data. The manifold itself is represented using a novel data structure, a multi-level manifold ensemble, which contains links between nodes in a single hierarchical structure, as well as links between different hierarchies, representing overlapping partitions. We show that this data structure allows both efficient localization and navigation on the manifold, for on-the-fly building of local nonlinear models (manifold charting). Our reconstruction framework was tested on pre- and postoperative X-ray datasets from patients who underwent spinal surgery. Compared to manual ground-truth, our method achieves a 3D reconstruction accuracy of 2.37 +/- 0.85 mm for postoperative spine models and can deal with severe cases of scoliosis.

Force of habit: shrubs, trees and contingent evolution of wood anatomical diversity using Croton (Euphorbiaceae) as a model system

Treesearch

Rafael Arévalo; Benjamin W. van Ee; Ricarda Riina; Paul E. Berry; Alex C. Wiedenhoeft

2017-01-01

Background and Aims Wood is a major innovation of land plants, and is usually a central component of the body plan for two major plant habits: shrubs and trees. Wood anatomical syndromes vary between shrubs and trees, but no prior work has explicitly evaluated the contingent evolution of wood anatomical diversity in the context...

PIV-measured versus CFD-predicted flow dynamics in anatomically realistic cerebral aneurysm models.

PubMed

Ford, Matthew D; Nikolov, Hristo N; Milner, Jaques S; Lownie, Stephen P; Demont, Edwin M; Kalata, Wojciech; Loth, Francis; Holdsworth, David W; Steinman, David A

2008-04-01

Computational fluid dynamics (CFD) modeling of nominally patient-specific cerebral aneurysms is increasingly being used as a research tool to further understand the development, prognosis, and treatment of brain aneurysms. We have previously developed virtual angiography to indirectly validate CFD-predicted gross flow dynamics against the routinely acquired digital subtraction angiograms. Toward a more direct validation, here we compare detailed, CFD-predicted velocity fields against those measured using particle imaging velocimetry (PIV). Two anatomically realistic flow-through phantoms, one a giant internal carotid artery (ICA) aneurysm and the other a basilar artery (BA) tip aneurysm, were constructed of a clear silicone elastomer. The phantoms were placed within a computer-controlled flow loop, programed with representative flow rate waveforms. PIV images were collected on several anterior-posterior (AP) and lateral (LAT) planes. CFD simulations were then carried out using a well-validated, in-house solver, based on micro-CT reconstructions of the geometries of the flow-through phantoms and inlet/outlet boundary conditions derived from flow rates measured during the PIV experiments. PIV and CFD results from the central AP plane of the ICA aneurysm showed a large stable vortex throughout the cardiac cycle. Complex vortex dynamics, captured by PIV and CFD, persisted throughout the cardiac cycle on the central LAT plane. Velocity vector fields showed good overall agreement. For the BA, aneurysm agreement was more compelling, with both PIV and CFD similarly resolving the dynamics of counter-rotating vortices on both AP and LAT planes. Despite the imposition of periodic flow boundary conditions for the CFD simulations, cycle-to-cycle fluctuations were evident in the BA aneurysm simulations, which agreed well, in terms of both amplitudes and spatial distributions, with cycle-to-cycle fluctuations measured by PIV in the same geometry. The overall good agreement between PIV and CFD suggests that CFD can reliably predict the details of the intra-aneurysmal flow dynamics observed in anatomically realistic in vitro models. Nevertheless, given the various modeling assumptions, this does not prove that they are mimicking the actual in vivo hemodynamics, and so validations against in vivo data are encouraged whenever possible.

Joint kinematic calculation based on clinical direct kinematic versus inverse kinematic gait models.

PubMed

Kainz, H; Modenese, L; Lloyd, D G; Maine, S; Walsh, H P J; Carty, C P

2016-06-14

Most clinical gait laboratories use the conventional gait analysis model. This model uses a computational method called Direct Kinematics (DK) to calculate joint kinematics. In contrast, musculoskeletal modelling approaches use Inverse Kinematics (IK) to obtain joint angles. IK allows additional analysis (e.g. muscle-tendon length estimates), which may provide valuable information for clinical decision-making in people with movement disorders. The twofold aims of the current study were: (1) to compare joint kinematics obtained by a clinical DK model (Vicon Plug-in-Gait) with those produced by a widely used IK model (available with the OpenSim distribution), and (2) to evaluate the difference in joint kinematics that can be solely attributed to the different computational methods (DK versus IK), anatomical models and marker sets by using MRI based models. Eight children with cerebral palsy were recruited and presented for gait and MRI data collection sessions. Differences in joint kinematics up to 13° were found between the Plug-in-Gait and the gait 2392 OpenSim model. The majority of these differences (94.4%) were attributed to differences in the anatomical models, which included different anatomical segment frames and joint constraints. Different computational methods (DK versus IK) were responsible for only 2.7% of the differences. We recommend using the same anatomical model for kinematic and musculoskeletal analysis to ensure consistency between the obtained joint angles and musculoskeletal estimates. Copyright © 2016 Elsevier Ltd. All rights reserved.

Active shape models incorporating isolated landmarks for medical image annotation

NASA Astrophysics Data System (ADS)

Norajitra, Tobias; Meinzer, Hans-Peter; Stieltjes, Bram; Maier-Hein, Klaus H.

2014-03-01

Apart from their robustness in anatomic surface segmentation, purely surface based 3D Active Shape Models lack the ability to automatically detect and annotate non-surface key points of interest. However, annotation of anatomic landmarks is desirable, as it yields additional anatomic and functional information. Moreover, landmark detection might help to further improve accuracy during ASM segmentation. We present an extension of surface-based 3D Active Shape Models incorporating isolated non-surface landmarks. Positions of isolated and surface landmarks are modeled conjoint within a point distribution model (PDM). Isolated landmark appearance is described by a set of haar-like features, supporting local landmark detection on the PDM estimates using a kNN-Classi er. Landmark detection was evaluated in a leave-one-out cross validation on a reference dataset comprising 45 CT volumes of the human liver after shape space projection. Depending on the anatomical landmark to be detected, our experiments have shown in about 1/4 up to more than 1/2 of all test cases a signi cant improvement in detection accuracy compared to the position estimates delivered by the PDM. Our results encourage further research with regard to the combination of shape priors and machine learning for landmark detection within the Active Shape Model Framework.

Evaluation of influences of the Viennese Anatomical School on the work of the Croatian Anatomist Jelena Krmpotic-Nemanic.

PubMed

Dinjar, Kristijan; Toth, Jurica; Atalic, Bruno; Radanovic, Danijela; Maric, Svjetlana

2012-01-01

This paper tries to evaluate the connections between the Viennese Anatomical School and the Croatian Anatomist Jelena Krmpotic-Nemanic. 17 papers written by Professor Jelena Krmpotic-Nemanic in the last decade of her life were chosen for analyses. According to their themes they could be divided into three groups: ones which evaluate the anatomical terminology, ones which research the development of anatomical structures, and ones which describe the anatomical variations. Mentioned papers were analysed through their topics, methods of research and cited references. Analyses of the mentioned papers revealed the indirect link between the Viennese Anatomical School and the Professor Jelena Krmpotic-Nemanic, through her mentor Professor Drago Perovic, regarding the themes and the methods of her anatomical researches. It has also showed her preference for Austrian and German anatomical textbooks and atlases, primarily ones published in Vienna and Jena, rather than English and American ones. Finally, her direct connections with the Viennese Institute for the History of Medicine and the Viennese Josephinum Wax Models Museum were emphasized. Mentioned indirect and direct influences of the Viennese Anatomical School on the work of Professor Jelena Krmpotic-Nemanic were critically appraised.

How and why does the areole meristem move in Echinocereus (Cactaceae)?

PubMed

Sánchez, Daniel; Grego-Valencia, Dalia; Terrazas, Teresa; Arias, Salvador

2015-01-01

In Cactaceae, the areole is the organ that forms the leaves, spines and buds. Apparently, the genus Echinocereus develops enclosed buds that break through the epidermis of the stem adjacent to the areole; this trait most likely represents a synapomorphy of Echinocereus. The development of the areole is investigated here in order to understand the anatomical modifications that lead to internal bud development and to supplement anatomical knowledge of plants that do not behave according to classical shoot theory. The external morphology of the areole was documented and the anatomy was studied using tissue clearing, scanning electron microscopy and light microscopy for 50 species that represent the recognized clades and sections of the traditional classification of the genus, including Morangaya pensilis (Echinocereus pensilis). In Echinocereus, the areole is sealed by the periderm, and the areole meristem is moved and enclosed by the differential growth of the epidermis and surrounding cortex. The enclosed areole meristem is differentiated in a vegetative or floral bud, which develops internally and breaks through the epidermis of the stem. In Morangaya pensilis, the areole is not sealed by the periderm and the areole meristem is not enclosed. The enclosed areole meristem and internal bud development are understood to be an adaptation to protect the meristem and the bud from low temperatures. The anatomical evidence supports the hypothesis that the enclosed bud represents one synapomorphy for Echinocereus and also supports the exclusion of Morangaya from Echinocereus. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Influence of anatomical dominance and hypertension on coronary conduit arterial and microcirculatory flow patterns: a multiscale modeling study.

PubMed

Mynard, Jonathan P; Smolich, Joseph J

2016-07-01

Coronary hemodynamics are known to be affected by intravascular and extravascular factors that vary regionally and transmurally between the perfusion territories of left and right coronary arteries. However, despite clinical evidence that left coronary arterial dominance portends greater cardiovascular risk, relatively little is known about the effects of left or right dominance on regional conduit arterial and microcirculatory blood flow patterns, particularly in the presence of systemic or pulmonary hypertension. We addressed this issue using a multiscale numerical model of the human coronary circulation situated in a closed-loop cardiovascular model. The coronary model represented left or right dominant anatomies and accounted for transmural and regional differences in vascular properties and extravascular compression. Regional coronary flow dynamics of the two anatomical variants were compared under normotensive conditions, raised systemic or pulmonary pressures with maintained flow demand, and after accounting for adaptations known to occur in acute and chronic hypertensive states. Key findings were that 1) right coronary arterial flow patterns were strongly influenced by dominance and systemic/pulmonary hypertension; 2) dominance had minor effects on left coronary arterial and all microvascular flow patterns (aside from mean circumflex flow); 3) although systemic hypertension favorably increased perfusion pressure, this benefit varied regionally and transmurally and was offset by increased left ventricular and septal flow demands; and 4) pulmonary hypertension had a substantial negative effect on right ventricular and septal flows, which was exacerbated by greater metabolic demands. These findings highlight the importance of interactions between coronary arterial dominance and hypertension in modulating coronary hemodynamics. Copyright © 2016 the American Physiological Society.

[Modelling science. The ceroplastics of Ignacio Lacaba in the Colegio de Cirugía de San Carlos, Madrid].

PubMed

Morente, Maribel

2016-01-01

Models made of wax had enormous diffusion in the anatomical teaching of the 18th century. It transcended the borders of a science that impregnated with scientific knowledge the artistic expression of beauty. Based on this premise, the San Carlos Royal College of Surgery created in Madrid a large collection of anatomical models, which is currently maintained by the Javier Puerta Anatomy Museum in the School of Medicine at Madrid Complutense University. The collection began in 1786 with Ignacio Lacaba, the first dissector of the Surgery College of Madrid, whose artistic sensibility and deep knowledge of anatomy contributed and facilitated harmonization between the work of the wax sculptors and language and anatomical expression.

Anatomical and spatial matching in imitation: Evidence from left and right brain-damaged patients.

PubMed

Mengotti, Paola; Ripamonti, Enrico; Pesavento, Valentina; Rumiati, Raffaella Ida

2015-12-01

Imitation is a sensorimotor process whereby the visual information present in the model's movement has to be coupled with the activation of the motor system in the observer. This also implies that greater the similarity between the seen and the produced movement, the easier it will be to execute the movement, a process also known as ideomotor compatibility. Two components can influence the degree of similarity between two movements: the anatomical and the spatial component. The anatomical component is present when the model and imitator move the same body part (e.g., the right hand) while the spatial component is present when the movement of the model and that of the imitator occur at the same spatial position. Imitation can be achieved by relying on both components, but typically the model's and imitator's movements are matched either anatomically or spatially. The aim of this study was to ascertain the contribution of the left and right hemisphere to the imitation accomplished either with anatomical or spatial matching (or with both). Patients with unilateral left and right brain damage performed an ideomotor task and a gesture imitation task. Lesions in the left and right hemispheres gave rise to different performance deficits. Patients with lesions in the left hemisphere showed impaired imitation when anatomical matching was required, and patients with lesions in the right hemisphere showed impaired imitation when spatial matching was required. Lesion analysis further revealed a differential involvement of left and right hemispheric regions, such as the parietal opercula, in supporting imitation in the ideomotor task. Similarly, gesture imitation seemed to rely on different regions in the left and right hemisphere, such as parietal regions in the left hemisphere and premotor, somatosensory and subcortical regions in the right hemisphere. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cardiovascular cast model fabrication and casting effectiveness evaluation in fetus with severe congenital heart disease or normal heart.

PubMed

Wang, Yu; Cao, Hai-yan; Xie, Ming-xing; He, Lin; Han, Wei; Hong, Liu; Peng, Yuan; Hu, Yun-fei; Song, Ben-cai; Wang, Jing; Wang, Bin; Deng, Cheng

2016-04-01

To investigate the application and effectiveness of vascular corrosion technique in preparing fetal cardiovascular cast models, 10 normal fetal heart specimens with other congenital disease (control group) and 18 specimens with severe congenital heart disease (case group) from induced abortions were enrolled in this study from March 2013 to June 2015 in our hospital. Cast models were prepared by injecting casting material into vascular lumen to demonstrate real geometries of fetal cardiovascular system. Casting effectiveness was analyzed in terms of local anatomic structures and different anatomical levels (including overall level, atrioventricular and great vascular system, left-sided and right-sided heart), as well as different trimesters of pregnancy. In our study, all specimens were successfully casted. Casting effectiveness analysis of local anatomic structures showed a mean score from 1.90±1.45 to 3.60±0.52, without significant differences between case and control groups in most local anatomic structures except left ventricle, which had a higher score in control group (P=0.027). Inter-group comparison of casting effectiveness in different anatomical levels showed no significant differences between the two groups. Intra-group comparison also revealed undifferentiated casting effectiveness between atrioventricular and great vascular system, or left-sided and right-sided heart in corresponding group. Third-trimester group had a significantly higher perfusion score in great vascular system than second-trimester group (P=0.046), while the other anatomical levels displayed no such difference. Vascular corrosion technique can be successfully used in fabrication of fetal cardiovascular cast model. It is also a reliable method to demonstrate three-dimensional anatomy of severe congenital heart disease and normal heart in fetus.

Motivation and Organizational Principles for Anatomical Knowledge Representation

PubMed Central

Rosse, Cornelius; Mejino, José L.; Modayur, Bharath R.; Jakobovits, Rex; Hinshaw, Kevin P.; Brinkley, James F.

1998-01-01

Abstract Objective: Conceptualization of the physical objects and spaces that constitute the human body at the macroscopic level of organization, specified as a machine-parseable ontology that, in its human-readable form, is comprehensible to both expert and novice users of anatomical information. Design: Conceived as an anatomical enhancement of the UMLS Semantic Network and Metathesaurus, the anatomical ontology was formulated by specifying defining attributes and differentia for classes and subclasses of physical anatomical entities based on their partitive and spatial relationships. The validity of the classification was assessed by instantiating the ontology for the thorax. Several transitive relationships were used for symbolically modeling aspects of the physical organization of the thorax. Results: By declaring Organ as the macroscopic organizational unit of the body, and defining the entities that constitute organs and higher level entities constituted by organs, all anatomical entities could be assigned to one of three top level classes (Anatomical structure, Anatomical spatial entity and Body substance). The ontology accommodates both the systemic and regional (topographical) views of anatomy, as well as diverse clinical naming conventions of anatomical entities. Conclusions: The ontology formulated for the thorax is extendible to microscopic and cellular levels, as well as to other body parts, in that its classes subsume essentially all anatomical entities that constitute the body. Explicit definitions of these entities and their relationships provide the first requirement for standards in anatomical concept representation. Conceived from an anatomical viewpoint, the ontology can be generalized and mapped to other biomedical domains and problem solving tasks that require anatomical knowledge. PMID:9452983

Human swallowing simulation based on videofluorography images using Hamiltonian MPS method

NASA Astrophysics Data System (ADS)

Kikuchi, Takahiro; Michiwaki, Yukihiro; Kamiya, Tetsu; Toyama, Yoshio; Tamai, Tasuku; Koshizuka, Seiichi

2015-09-01

In developed nations, swallowing disorders and aspiration pneumonia have become serious problems. We developed a method to simulate the behavior of the organs involved in swallowing to clarify the mechanisms of swallowing and aspiration. The shape model is based on anatomically realistic geometry, and the motion model utilizes forced displacements based on realistic dynamic images to reflect the mechanisms of human swallowing. The soft tissue organs are modeled as nonlinear elastic material using the Hamiltonian MPS method. This method allows for stable simulation of the complex swallowing movement. A penalty method using metaballs is employed to simulate contact between organ walls and smooth sliding along the walls. We performed four numerical simulations under different analysis conditions to represent four cases of swallowing, including a healthy volunteer and a patient with a swallowing disorder. The simulation results were compared to examine the epiglottic downfolding mechanism, which strongly influences the risk of aspiration.

The impact of anthropometric patient-phantom matching on organ dose: A hybrid phantom study for fluoroscopy guided interventions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Perry B.; Geyer, Amy; Borrego, David

Purpose: To investigate the benefits and limitations of patient-phantom matching for determining organ dose during fluoroscopy guided interventions. Methods: In this study, 27 CT datasets representing patients of different sizes and genders were contoured and converted into patient-specific computational models. Each model was matched, based on height and weight, to computational phantoms selected from the UF hybrid patient-dependent series. In order to investigate the influence of phantom type on patient organ dose, Monte Carlo methods were used to simulate two cardiac projections (PA/left lateral) and two abdominal projections (RAO/LPO). Organ dose conversion coefficients were then calculated for each patient-specific andmore » patient-dependent phantom and also for a reference stylized and reference hybrid phantom. The coefficients were subsequently analyzed for any correlation between patient-specificity and the accuracy of the dose estimate. Accuracy was quantified by calculating an absolute percent difference using the patient-specific dose conversion coefficients as the reference. Results: Patient-phantom matching was shown most beneficial for estimating the dose to heavy patients. In these cases, the improvement over using a reference stylized phantom ranged from approximately 50% to 120% for abdominal projections and for a reference hybrid phantom from 20% to 60% for all projections. For lighter individuals, patient-phantom matching was clearly superior to using a reference stylized phantom, but not significantly better than using a reference hybrid phantom for certain fields and projections. Conclusions: The results indicate two sources of error when patients are matched with phantoms: Anatomical error, which is inherent due to differences in organ size and location, and error attributed to differences in the total soft tissue attenuation. For small patients, differences in soft tissue attenuation are minimal and are exceeded by inherent anatomical differences. For large patients, difference in soft tissue attenuation can be large. In these cases, patient-phantom matching proves most effective as differences in soft tissue attenuation are mitigated. With increasing obesity rates, overweight patients will continue to make up a growing fraction of all patients undergoing medical imaging. Thus, having phantoms that better represent this population represents a considerable improvement over previous methods. In response to this study, additional phantoms representing heavier weight percentiles will be added to the UFHADM and UFHADF patient-dependent series.« less

Computational representation of the aponeuroses as NURBS surfaces in 3D musculoskeletal models.

PubMed

Wu, Florence T H; Ng-Thow-Hing, Victor; Singh, Karan; Agur, Anne M; McKee, Nancy H

2007-11-01

Computational musculoskeletal (MSK) models - 3D graphics-based models that accurately simulate the anatomical architecture and/or the biomechanical behaviour of organ systems consisting of skeletal muscles, tendons, ligaments, cartilage and bones - are valued biomedical tools, with applications ranging from pathological diagnosis to surgical planning. However, current MSK models are often limited by their oversimplifications in anatomical geometries, sometimes lacking discrete representations of connective tissue components entirely, which ultimately affect their accuracy in biomechanical simulation. In particular, the aponeuroses - the flattened fibrous connective sheets connecting muscle fibres to tendons - have never been geometrically modeled. The initiative was thus to extend Anatomy3D - a previously developed software bundle for reconstructing muscle fibre architecture - to incorporate aponeurosis-modeling capacity. Two different algorithms for aponeurosis reconstruction were written in the MEL scripting language of the animation software Maya 6.0, using its NURBS (non-uniform rational B-splines) modeling functionality for aponeurosis surface representation. Both algorithms were validated qualitatively against anatomical and functional criteria.

Histological and reference system for the analysis of mouse intervertebral disc.

PubMed

Tam, Vivian; Chan, Wilson C W; Leung, Victor Y L; Cheah, Kathryn S E; Cheung, Kenneth M C; Sakai, Daisuke; McCann, Matthew R; Bedore, Jake; Séguin, Cheryle A; Chan, Danny

2018-01-01

A new scoring system based on histo-morphology of mouse intervertebral disc (IVD) was established to assess changes in different mouse models of IVD degeneration and repair. IVDs from mouse strains of different ages, transgenic mice, or models of artificially induced IVD degeneration were assessed. Morphological features consistently observed in normal, and early/later stages of degeneration were categorized into a scoring system focused on nucleus pulposus (NP) and annulus fibrosus (AF) changes. "Normal NP" exhibited a highly cellularized cell mass that decreased with natural ageing and in disc degeneration. "Normal AF" consisted of distinct concentric lamellar structures, which was disrupted in severe degeneration. NP/AF clefts indicated more severe changes. Consistent scores were obtained between experienced and new users. Altogether, our scoring system effectively differentiated IVD changes in various strains of wild-type and genetically modified mice and in induced models of IVD degeneration, and is applicable from the post-natal stage to the aged mouse. This scoring tool and reference resource addresses a pressing need in the field for studying IVD changes and cross-study comparisons in mice, and facilitates a means to normalize mouse IVD assessment between different laboratories. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:233-243, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

In vivo engineering of oncogenic chromosomal rearrangements with the CRISPR/Cas9 system

PubMed Central

Maddalo, Danilo; Manchado, Eusebio; Concepcion, Carla P.; Bonetti, Ciro; Vidigal, Joana A.; Han, Yoon-Chi; Ogrodowski, Paul; Crippa, Alessandra; Rekhtman, Natasha; de Stanchina, Elisa; Lowe, Scott W.; Ventura, Andrea

2014-01-01

Chromosomal rearrangements play a central role in the pathogenesis of human cancers and often result in the expression of therapeutically actionable gene fusions1. A recently discovered example is a fusion between the Echinoderm Microtubule-associated Protein-like 4 (EML4) and the Anaplastic Lymphoma Kinase (ALK) genes, generated by an inversion on the short arm of chromosome 2: inv(2)(p21p23). The EML4-ALK oncogene is detected in a subset of human non-small cell lung cancers (NSCLC)2 and is clinically relevant because it confers sensitivity to ALK inhibitors3. Despite their importance, modeling such genetic events in mice has proven challenging and requires complex manipulation of the germline. Here we describe an efficient method to induce specific chromosomal rearrangements in vivo using viral-mediated delivery of the CRISPR/Cas9 system to somatic cells of adult animals. We apply it to generate a mouse model of Eml4-Alk-driven lung cancer. The resulting tumors invariably harbor the Eml4-Alkinversion, express the Eml4-Alk fusion gene, display histo-pathologic and molecular features typical of ALK+ human NSCLCs, and respond to treatment with ALK-inhibitors. The general strategy described here substantially expands our ability to model human cancers in mice and potentially in other organisms. PMID:25337876

Discover mouse gene coexpression landscapes using dictionary learning and sparse coding.

PubMed

Li, Yujie; Chen, Hanbo; Jiang, Xi; Li, Xiang; Lv, Jinglei; Peng, Hanchuan; Tsien, Joe Z; Liu, Tianming

2017-12-01

Gene coexpression patterns carry rich information regarding enormously complex brain structures and functions. Characterization of these patterns in an unbiased, integrated, and anatomically comprehensive manner will illuminate the higher-order transcriptome organization and offer genetic foundations of functional circuitry. Here using dictionary learning and sparse coding, we derived coexpression networks from the space-resolved anatomical comprehensive in situ hybridization data from Allen Mouse Brain Atlas dataset. The key idea is that if two genes use the same dictionary to represent their original signals, then their gene expressions must share similar patterns, thereby considering them as "coexpressed." For each network, we have simultaneous knowledge of spatial distributions, the genes in the network and the extent a particular gene conforms to the coexpression pattern. Gene ontologies and the comparisons with published gene lists reveal biologically identified coexpression networks, some of which correspond to major cell types, biological pathways, and/or anatomical regions.

Pleistocene Homo sapiens from Middle Awash, Ethiopia.

PubMed

White, Tim D; Asfaw, Berhane; DeGusta, David; Gilbert, Henry; Richards, Gary D; Suwa, Gen; Howell, F Clark

2003-06-12

The origin of anatomically modern Homo sapiens and the fate of Neanderthals have been fundamental questions in human evolutionary studies for over a century. A key barrier to the resolution of these questions has been the lack of substantial and accurately dated African hominid fossils from between 100,000 and 300,000 years ago. Here we describe fossilized hominid crania from Herto, Middle Awash, Ethiopia, that fill this gap and provide crucial evidence on the location, timing and contextual circumstances of the emergence of Homo sapiens. Radioisotopically dated to between 160,000 and 154,000 years ago, these new fossils predate classic Neanderthals and lack their derived features. The Herto hominids are morphologically and chronologically intermediate between archaic African fossils and later anatomically modern Late Pleistocene humans. They therefore represent the probable immediate ancestors of anatomically modern humans. Their anatomy and antiquity constitute strong evidence of modern-human emergence in Africa.

Numerical compliance testing of human exposure to electromagnetic radiation from smart-watches.

PubMed

Hong, Seon-Eui; Lee, Ae-Kyoung; Kwon, Jong-Hwa; Pack, Jeong-Ki

2016-10-07

In this study, we investigated the electromagnetic dosimetry for smart-watches. At present, the standard for compliance testing of body-mounted and handheld devices specifies the use of a flat phantom to provide conservative estimates of the peak spatial-averaged specific absorption rate (SAR). This means that the estimated SAR using a flat phantom should be higher than the SAR in the exposure part of an anatomical human-body model. To verify this, we numerically calculated the SAR for a flat phantom and compared it with the numerical calculation of the SAR for four anatomical human-body models of different ages. The numerical analysis was performed using the finite difference time domain method (FDTD). The smart-watch models were used in the three antennas: the shorted planar inverted-F antenna (PIFA), loop antenna, and monopole antenna. Numerical smart-watch models were implemented for cellular commutation and wireless local-area network operation at 835, 1850, and 2450 MHz. The peak spatial-averaged SARs of the smart-watch models are calculated for the flat phantom and anatomical human-body model for the wrist-worn and next to mouth positions. The results show that the flat phantom does not provide a consistent conservative SAR estimate. We concluded that the difference in the SAR results between an anatomical human-body model and a flat phantom can be attributed to the different phantom shapes and tissue structures.

Numerical compliance testing of human exposure to electromagnetic radiation from smart-watches

NASA Astrophysics Data System (ADS)

Hong, Seon-Eui; Lee, Ae-Kyoung; Kwon, Jong-Hwa; Pack, Jeong-Ki

2016-10-01

In this study, we investigated the electromagnetic dosimetry for smart-watches. At present, the standard for compliance testing of body-mounted and handheld devices specifies the use of a flat phantom to provide conservative estimates of the peak spatial-averaged specific absorption rate (SAR). This means that the estimated SAR using a flat phantom should be higher than the SAR in the exposure part of an anatomical human-body model. To verify this, we numerically calculated the SAR for a flat phantom and compared it with the numerical calculation of the SAR for four anatomical human-body models of different ages. The numerical analysis was performed using the finite difference time domain method (FDTD). The smart-watch models were used in the three antennas: the shorted planar inverted-F antenna (PIFA), loop antenna, and monopole antenna. Numerical smart-watch models were implemented for cellular commutation and wireless local-area network operation at 835, 1850, and 2450 MHz. The peak spatial-averaged SARs of the smart-watch models are calculated for the flat phantom and anatomical human-body model for the wrist-worn and next to mouth positions. The results show that the flat phantom does not provide a consistent conservative SAR estimate. We concluded that the difference in the SAR results between an anatomical human-body model and a flat phantom can be attributed to the different phantom shapes and tissue structures.

Anatomically realistic multiscale models of normal and abnormal gastrointestinal electrical activity

PubMed Central

Cheng, Leo K; Komuro, Rie; Austin, Travis M; Buist, Martin L; Pullan, Andrew J

2007-01-01

One of the major aims of the International Union of Physiological Sciences (IUPS) Physiome Project is to develop multiscale mathematical and computer models that can be used to help understand human health. We present here a small facet of this broad plan that applies to the gastrointestinal system. Specifically, we present an anatomically and physiologically based modelling framework that is capable of simulating normal and pathological electrical activity within the stomach and small intestine. The continuum models used within this framework have been created using anatomical information derived from common medical imaging modalities and data from the Visible Human Project. These models explicitly incorporate the various smooth muscle layers and networks of interstitial cells of Cajal (ICC) that are known to exist within the walls of the stomach and small bowel. Electrical activity within individual ICCs and smooth muscle cells is simulated using a previously published simplified representation of the cell level electrical activity. This simulated cell level activity is incorporated into a bidomain representation of the tissue, allowing electrical activity of the entire stomach or intestine to be simulated in the anatomically derived models. This electrical modelling framework successfully replicates many of the qualitative features of the slow wave activity within the stomach and intestine and has also been used to investigate activity associated with functional uncoupling of the stomach. PMID:17457969

Development of an interactive anatomical three-dimensional eye model.

PubMed

Allen, Lauren K; Bhattacharyya, Siddhartha; Wilson, Timothy D

2015-01-01

The discrete anatomy of the eye's intricate oculomotor system is conceptually difficult for novice students to grasp. This is problematic given that this group of muscles represents one of the most common sites of clinical intervention in the treatment of ocular motility disorders and other eye disorders. This project was designed to develop a digital, interactive, three-dimensional (3D) model of the muscles and cranial nerves of the oculomotor system. Development of the 3D model utilized data from the Visible Human Project (VHP) dataset that was refined using multiple forms of 3D software. The model was then paired with a virtual user interface in order to create a novel 3D learning tool for the human oculomotor system. Development of the virtual eye model was done while attempting to adhere to the principles of cognitive load theory (CLT) and the reduction of extraneous load in particular. The detailed approach, digital tools employed, and the CLT guidelines are described herein. © 2014 American Association of Anatomists.

An insect-inspired model for visual binding I: learning objects and their characteristics.

PubMed

Northcutt, Brandon D; Dyhr, Jonathan P; Higgins, Charles M

2017-04-01

Visual binding is the process of associating the responses of visual interneurons in different visual submodalities all of which are responding to the same object in the visual field. Recently identified neuropils in the insect brain termed optic glomeruli reside just downstream of the optic lobes and have an internal organization that could support visual binding. Working from anatomical similarities between optic and olfactory glomeruli, we have developed a model of visual binding based on common temporal fluctuations among signals of independent visual submodalities. Here we describe and demonstrate a neural network model capable both of refining selectivity of visual information in a given visual submodality, and of associating visual signals produced by different objects in the visual field by developing inhibitory neural synaptic weights representing the visual scene. We also show that this model is consistent with initial physiological data from optic glomeruli. Further, we discuss how this neural network model may be implemented in optic glomeruli at a neuronal level.

The avian embryo responding to microgravity of space flight

NASA Technical Reports Server (NTRS)

Hullinger, Ronald L.

1993-01-01

Of all the many potential and real microenvironmental influences, only gravity would appear to have remained relatively constant and ubiquitous for developing organisms. Histo- and organogenesis as well as differential growth of the embryo and fetus may have evolved with a constant environmental factor of gravity. Chick embryos of 2-day and 9-day stages of incubation were flown in an incubator on the Space Shuttle during a 9-day mission. Significant differences in embryo response to this microgravity environment were observed. This paper offers an analysis and suggests mechanisms which may contribute to these results.

Logistic Support and Insurgency. Guerrilla Sustainment and Applied Lessons of Soviet Insurgent Warfare: Why it Should Still be Studied

DTIC Science & Technology

2005-10-01

In su rgen t War fa re : Why I t Shou ld S t i l l Be S tud ied Graham H. Turbivi l le, J r. The views expressed in this publication are...Department of the Army, Office of the Chief of Military Histo- ry, draft translation of an assessment by D . Karov and V . Voizhanin, “Supply of Partisan...commanded by Hero of the Soviet Union V . S . Grizodubov. They carried out landings at partisan airfields, trans- ferred wounded soldiers, women and children

Value of 3D printing for the comprehension of surgical anatomy.

PubMed

Marconi, Stefania; Pugliese, Luigi; Botti, Marta; Peri, Andrea; Cavazzi, Emma; Latteri, Saverio; Auricchio, Ferdinando; Pietrabissa, Andrea

2017-10-01

In a preliminary experience, we claimed the potential value of 3D printing technology for pre-operative counseling and surgical planning. However, no objective analysis has ever assessed its additional benefit in transferring anatomical information from radiology to final users. We decided to validate the pre-operative use of 3D-printed anatomical models in patients with solid organs' diseases as a new tool to deliver morphological information. Fifteen patients scheduled for laparoscopic splenectomy, nephrectomy, or pancreatectomy were selected and, for each, a full-size 3D virtual anatomical object was reconstructed from a contrast-enhanced MDCT (Multiple Detector Computed Tomography) and then prototyped using a 3D printer. After having carefully evaluated-in a random sequence-conventional contrast MDCT scans, virtual 3D reconstructions on a flat monitor, and 3D-printed models of the same anatomy for each selected case, thirty subjects with different expertise in radiological imaging (10 medical students, 10 surgeons and 10 radiologists) were administered a multiple-item questionnaire. Crucial issues for the anatomical understanding and the pre-operative planning of the scheduled procedure were addressed. The visual and tactile inspection of 3D models allowed the best anatomical understanding, with faster and clearer comprehension of the surgical anatomy. As expected, less experienced medical students perceived the highest benefit (53.9% ± 4.14 of correct answers with 3D-printed models, compared to 53.4 % ± 4.6 with virtual models and 45.5% ± 4.6 with MDCT), followed by surgeons and radiologists. The average time spent by participants in 3D model assessing was shorter (60.67 ± 25.5 s) than the one of the corresponding virtual 3D reconstruction (70.8 ± 28.18 s) or conventional MDCT scan (127.04 ± 35.91 s). 3D-printed models help to transfer complex anatomical information to clinicians, resulting useful in the pre-operative planning, for intra-operative navigation and for surgical training purposes.

Professor Herman Burger (1893-1965), eminent teacher and scientist, who laid the theoretical foundations of vectorcardiography--and electrocardiography.

PubMed

van Herpen, Gerard

2014-01-01

Einthoven not only designed a high quality instrument, the string galvanometer, for recording the ECG, he also shaped the conceptual framework to understand it. He reduced the body to an equilateral triangle and the cardiac electric activity to a dipole, represented by an arrow (i.e. a vector) in the triangle's center. Up to the present day the interpretation of the ECG is based on the model of a dipole vector being projected on the various leads. The model is practical but intuitive, not physically founded. Burger analysed the relation between heart vector and leads according to the principles of physics. It then follows that an ECG lead must be treated as a vector (lead vector) and that the lead voltage is not simply proportional to the projection of the vector on the lead, but must be multiplied by the value (length) of the lead vector, the lead strength. Anatomical lead axis and electrical lead axis are different entities and the anatomical body space must be distinguished from electrical space. Appreciation of these underlying physical principles should contribute to a better understanding of the ECG. The development of these principles by Burger is described, together with some personal notes and a sketch of the personality of this pioneer of medical physics. Copyright © 2014. Published by Elsevier Inc.

["Norwegian scabies" in a wax model at the Pathology Museum of the University of Florence].

PubMed

Nesi, Gabriella; Santi, Raffaella; Sestini, Serena; De Giorgi, Vincenzo; Taddei, Gian Luigi

2008-01-01

The reproduction in wax of anatomic specimens is considered a glorious Italian tradition, particularly in Florence. Indeed, the work of wax masters which was cultivated for ex-votos and statuary models, together with the development of anatomic studies under the guidance of Paolo Mascagni at the end of the eighteenth century, gave origin to several collections of waxes, among which the collection of the Museum of Anatomic Pathology holds undoubted interest. The so-called "leper", a full-scale reproduction by Luigi Calamai of a man affected with Norwegian scabies, a rare skin disease, is considered the symbol of the Museum.

Structural analysis of determinants of histo-blood group antigen binding specificity in genogroup I noroviruses.

PubMed

Shanker, Sreejesh; Czako, Rita; Sankaran, Banumathi; Atmar, Robert L; Estes, Mary K; Prasad, B V Venkataram

2014-06-01

Human noroviruses (NoVs) cause acute epidemic gastroenteritis. Susceptibility to the majority of NoV infections is determined by genetically controlled secretor-dependent expression of histo-blood group antigens (HBGAs), which are also critical for NoV attachment to host cells. Human NoVs are classified into two major genogroups (genogroup I [GI] and GII), with each genogroup further divided into several genotypes. GII NoVs are more prevalent and exhibit periodic emergence of new variants, suggested to be driven by altered HBGA binding specificities and antigenic drift. Recent epidemiological studies show increased activity among GI NoVs, with some members showing the ability to bind nonsecretor HBGAs. NoVs bind HBGAs through the protruding (P) domain of the major capsid protein VP1. GI NoVs, similar to GII, exhibit significant sequence variations in the P domain; it is unclear how these variations affect HBGA binding specificities. To understand the determinants of possible strain-specific HBGA binding among GI NoVs, we determined the structure of the P domain of a GI.7 clinical isolate and compared it to the previously determined P domain structures of GI.1 and GI.2 strains. Our crystallographic studies revealed significant structural differences, particularly in the loop regions of the GI.7 P domain, altering its surface topography and electrostatic landscape and potentially indicating antigenic variation. The GI.7 strain bound to H- and A-type, Lewis secretor, and Lewis nonsecretor families of HBGAs, allowing us to further elucidate the structural determinants of nonsecretor HBGA binding among GI NoVs and to infer several contrasting and generalizable features of HBGA binding in the GI NoVs. Human noroviruses (NoVs) cause acute epidemic gastroenteritis. Recent epidemiological studies have shown increased prevalence of genogroup I (GI) NoVs. Although secretor-positive status is strongly correlated with NoV infection, cases of NoV infection associated with secretor-negative individuals are reported. Biochemical studies have shown that GI NoVs exhibit genotype-dependent binding to nonsecretor histo-blood group antigens (HBGAs). From our crystallographic studies of a GI.7 NoV, in comparison with previous studies on GI.1 and GI.2 NoVs, we show that genotypic differences translate to extensive structural changes in the loop regions that significantly alter the surface topography and electrostatic landscape of the P domain; these features may be indicative of antigenic variations contributing to serotypic differentiation in GI NoVs and also differential modulation of the HBGA binding characteristics. A significant finding is that the threshold length and the structure of one of the loops are critical determinants in the binding of GI NoVs to nonsecretor HBGAs.

Computational fluid dynamics endpoints to characterize obstructive sleep apnea syndrome in children

PubMed Central

Luo, Haiyan; Persak, Steven C.; Sin, Sanghun; McDonough, Joseph M.; Isasi, Carmen R.; Arens, Raanan

2013-01-01

Computational fluid dynamics (CFD) analysis may quantify the severity of anatomical airway restriction in obstructive sleep apnea syndrome (OSAS) better than anatomical measurements alone. However, optimal CFD model endpoints to characterize or assess OSAS have not been determined. To model upper airway fluid dynamics using CFD and investigate the strength of correlation between various CFD endpoints, anatomical endpoints, and OSAS severity, in obese children with OSAS and controls. CFD models derived from magnetic resonance images were solved at subject-specific peak tidal inspiratory flow; pressure at the choanae was set by nasal resistance. Model endpoints included airway wall minimum pressure (Pmin), flow resistance in the pharynx (Rpharynx), and pressure drop from choanae to a minimum cross section where tonsils and adenoids constrict the pharynx (dPTAmax). Significance of endpoints was analyzed using paired comparisons (t-test or Wilcoxon signed rank test) and Spearman correlation. Fifteen subject pairs were analyzed. Rpharynx and dPTAmax were higher in OSAS than control and most significantly correlated to obstructive apnea-hypopnea index (oAHI), r = 0.48 and r = 0.49, respectively (P < 0.01). Airway minimum cross-sectional correlation to oAHI was weaker (r = −0.39); Pmin was not significantly correlated. CFD model endpoints based on pressure drops in the pharynx were more closely associated with the presence and severity of OSAS than pressures including nasal resistance, or anatomical endpoints. This study supports the usefulness of CFD to characterize anatomical restriction of the pharynx and as an additional tool to evaluate subjects with OSAS. PMID:24265282

Learning-based stochastic object models for characterizing anatomical variations

NASA Astrophysics Data System (ADS)

Dolly, Steven R.; Lou, Yang; Anastasio, Mark A.; Li, Hua

2018-03-01

It is widely known that the optimization of imaging systems based on objective, task-based measures of image quality via computer-simulation requires the use of a stochastic object model (SOM). However, the development of computationally tractable SOMs that can accurately model the statistical variations in human anatomy within a specified ensemble of patients remains a challenging task. Previously reported numerical anatomic models lack the ability to accurately model inter-patient and inter-organ variations in human anatomy among a broad patient population, mainly because they are established on image data corresponding to a few of patients and individual anatomic organs. This may introduce phantom-specific bias into computer-simulation studies, where the study result is heavily dependent on which phantom is used. In certain applications, however, databases of high-quality volumetric images and organ contours are available that can facilitate this SOM development. In this work, a novel and tractable methodology for learning a SOM and generating numerical phantoms from a set of volumetric training images is developed. The proposed methodology learns geometric attribute distributions (GAD) of human anatomic organs from a broad patient population, which characterize both centroid relationships between neighboring organs and anatomic shape similarity of individual organs among patients. By randomly sampling the learned centroid and shape GADs with the constraints of the respective principal attribute variations learned from the training data, an ensemble of stochastic objects can be created. The randomness in organ shape and position reflects the learned variability of human anatomy. To demonstrate the methodology, a SOM of an adult male pelvis is computed and examples of corresponding numerical phantoms are created.

Dysfunctions of the basal ganglia-cerebellar-thalamo-cortical system produce motor tics in Tourette syndrome

PubMed Central

Arbib, Michael A.; Baldassarre, Gianluca

2017-01-01

Motor tics are a cardinal feature of Tourette syndrome and are traditionally associated with an excess of striatal dopamine in the basal ganglia. Recent evidence increasingly supports a more articulated view where cerebellum and cortex, working closely in concert with basal ganglia, are also involved in tic production. Building on such evidence, this article proposes a computational model of the basal ganglia-cerebellar-thalamo-cortical system to study how motor tics are generated in Tourette syndrome. In particular, the model: (i) reproduces the main results of recent experiments about the involvement of the basal ganglia-cerebellar-thalamo-cortical system in tic generation; (ii) suggests an explanation of the system-level mechanisms underlying motor tic production: in this respect, the model predicts that the interplay between dopaminergic signal and cortical activity contributes to triggering the tic event and that the recently discovered basal ganglia-cerebellar anatomical pathway may support the involvement of the cerebellum in tic production; (iii) furnishes predictions on the amount of tics generated when striatal dopamine increases and when the cortex is externally stimulated. These predictions could be important in identifying new brain target areas for future therapies. Finally, the model represents the first computational attempt to study the role of the recently discovered basal ganglia-cerebellar anatomical links. Studying this non-cortex-mediated basal ganglia-cerebellar interaction could radically change our perspective about how these areas interact with each other and with the cortex. Overall, the model also shows the utility of casting Tourette syndrome within a system-level perspective rather than viewing it as related to the dysfunction of a single brain area. PMID:28358814

Dysfunctions of the basal ganglia-cerebellar-thalamo-cortical system produce motor tics in Tourette syndrome.

PubMed

Caligiore, Daniele; Mannella, Francesco; Arbib, Michael A; Baldassarre, Gianluca

2017-03-01

Motor tics are a cardinal feature of Tourette syndrome and are traditionally associated with an excess of striatal dopamine in the basal ganglia. Recent evidence increasingly supports a more articulated view where cerebellum and cortex, working closely in concert with basal ganglia, are also involved in tic production. Building on such evidence, this article proposes a computational model of the basal ganglia-cerebellar-thalamo-cortical system to study how motor tics are generated in Tourette syndrome. In particular, the model: (i) reproduces the main results of recent experiments about the involvement of the basal ganglia-cerebellar-thalamo-cortical system in tic generation; (ii) suggests an explanation of the system-level mechanisms underlying motor tic production: in this respect, the model predicts that the interplay between dopaminergic signal and cortical activity contributes to triggering the tic event and that the recently discovered basal ganglia-cerebellar anatomical pathway may support the involvement of the cerebellum in tic production; (iii) furnishes predictions on the amount of tics generated when striatal dopamine increases and when the cortex is externally stimulated. These predictions could be important in identifying new brain target areas for future therapies. Finally, the model represents the first computational attempt to study the role of the recently discovered basal ganglia-cerebellar anatomical links. Studying this non-cortex-mediated basal ganglia-cerebellar interaction could radically change our perspective about how these areas interact with each other and with the cortex. Overall, the model also shows the utility of casting Tourette syndrome within a system-level perspective rather than viewing it as related to the dysfunction of a single brain area.

Development of a wearable microwave bladder monitor for the management and treatment of urinary incontinence

NASA Astrophysics Data System (ADS)

Krewer, F.; Morgan, F.; Jones, E.; Glavin, M.; O'Halloran, M.

2014-05-01

Urinary incontinence is defined as the inability to stop the flow of urine from the bladder. In the US alone, the annual societal cost of incontinence-related care is estimated at 12.6 billion dollars. Clinicians agree that those suffering from urinary incontinence would greatly benefit from a wearable system that could continually monitor the bladder, providing continuous feedback to the patient. While existing ultrasound-based solutions are highly accurate, they are severely limited by form-factor, battery size, cost and ease of use. In this study the authors propose an alternative bladder-state sensing system, based on Ultra Wideband (UWB) Radar. As part of an initial proof-of-concept, the authors developed one of the first dielectrically and anatomically-representative Finite Difference Time Domain models of the pelvis. These models (one male and one female) are derived from Magnetic Resonance images provided by the IT'IS Foundation. These IT'IS models provide the foundation upon which an anatomically-plausible bladder growth model was constructed. The authors employed accurate multi-pole Debye models to simulate the dielectric properties of each of the pelvic tissues. Two-dimensional Finite Difference Time Domain (FDTD) simulations were completed for a range of bladder volumes. Relevant features were extracted from the FDTD-derived signals using Principle Component Analysis (PCA) and then classified using a k-Nearest-Neighbour and Support Vector Machine algorithms (incorporating the Leave-one-out cross-validation approach). Additionally the authors investigated the effects of signal fidelity, noise and antenna movement relative to the target as potential sources of error. The results of this initial study provide strong motivation for further research into this timely application, particularly in the context of an ageing population.

The biomechanical analysis of three-dimensional distal radius fracture model with different fixed splints.

PubMed

Hua, Zhen; Wang, Jian-Wei; Lu, Zhen-Fei; Ma, Jian-Wei; Yin, Heng

2018-01-01

The distal radius fracture is one of the common clinical fractures. At present, there are no reports regarding application of the finite element method in studying the mechanism of Colles fracture and the biomechanical behavior when using splint fixation. To explore the mechanism of Colles fracture and the biomechanical behavior when using different fixed splints. Based on the CT scanning images of forearm for a young female volunteer, by using model construction technology combined with RPOE and ANSYS software, a 3-D distal radius fracture forearm finite element model with a real shape and bioactive materials is built. The material tests are performed to obtain the mechanical properties of the paper-based splint, the willow splint and the anatomical splint. The numerical results are compared with the experimental results to verify the correctness of the presented model. Based on the verified model, the stress distribution of different tissues are analyzed. Finally, the clinical tests are performed to observe and verify that the anatomical splint is the best fit for human body. Using the three kinds of splints, the transferred bone stress focus on the distal radius and ulna, which is helpful to maintain the stability of fracture. Also the stress is accumulated in the distal radius which may be attributed to flexion position. Such stress distribution may be helpful to maintain the ulnar declination. By comparing the simulation results with the experimental observations, the anatomical splint has the best fitting to the limb, which can effectively avoid the local compression. The anatomical splint is the most effective for fixing and curing the fracture. The presented model can provide theoretical basis and technical guide for further investigating mechanism of distal radius fracture and clinical application of anatomical splint.

Development of a quantitative multivariable radiographic method to evaluate anatomic changes associated with laminitis in the forefeet of donkeys.

PubMed

Collins, Simon N; Dyson, Sue J; Murray, Rachel C; Newton, J Richard; Burden, Faith; Trawford, Andrew F

2012-08-01

To establish and validate an objective method of radiographic diagnosis of anatomic changes in laminitic forefeet of donkeys on the basis of data from a comprehensive series of radiographic measurements. 85 donkeys with and 85 without forelimb laminitis for baseline data determination; a cohort of 44 donkeys with and 18 without forelimb laminitis was used for validation analyses. For each donkey, lateromedial radiographic views of 1 weight-bearing forelimb were obtained; images from 11 laminitic and 2 nonlaminitic donkeys were excluded (motion artifact) from baseline data determination. Data from an a priori selection of 19 measurements of anatomic features of laminitic and nonlaminitic donkey feet were analyzed by use of a novel application of multivariate statistical techniques. The resultant diagnostic models were validated in a blinded manner with data from the separate cohort of laminitic and nonlaminitic donkeys. Data were modeled, and robust statistical rules were established for the diagnosis of anatomic changes within laminitic donkey forefeet. Component 1 scores ≤ -3.5 were indicative of extreme anatomic change, and scores from -2.0 to 0.0 denoted modest change. Nonlaminitic donkeys with a score from 0.5 to 1.0 should be considered as at risk for laminitis. Results indicated that the radiographic procedures evaluated can be used for the identification, assessment, and monitoring of anatomic changes associated with laminitis. Screening assessments by use of this method may enable early detection of mild anatomic change and identification of at-risk donkeys.

Inexpensive anatomical trainer for bronchoscopy.

PubMed

Di Domenico, Stefano; Simonassi, Claudio; Chessa, Leonardo

2007-08-01

Flexible fiberoptic bronchoscopy is an indispensable tool for optimal management of intensive care unit patients. However, the acquisition of sufficient training in bronchoscopy is not straightforward during residency, because of technical and ethical problems. Moreover, the use of commercial simulators is limited by their high cost. In order to overcome these limitations, we realized a low-cost anatomical simulator to acquire and maintain the basic skill to perform bronchoscopy in ventilated patients. We used 1.5 mm diameter iron wire to construct the bronchial tree scaffold; glazier-putty was applied to create the anatomical model. The model was covered by several layers of newspaper strips previously immersed in water and vinilic glue. When the model completely dried up, it was detached from the scaffold by cutting it into six pieces, it was reassembled, painted and fitted with an endotracheal tube. We used very cheap material and the final cost was euro16. The trainer resulted in real-scale and anatomically accurate, with appropriate correspondence on endoscopic view between model and patients. All bronchial segments can be explored and easily identified by endoscopic and external vision. This cheap simulator is a valuable tool for practicing, particularly in a hospital with limited resources for medical training.

Effect of anatomy on human nasal air flow and odorant transport patterns: implications for olfaction.

PubMed

Zhao, Kai; Scherer, Peter W; Hajiloo, Shoreh A; Dalton, Pamela

2004-06-01

Recent studies that have compared CT or MRI images of an individual's nasal anatomy and measures of their olfactory sensitivity have found a correlation between specific anatomical areas and performance on olfactory assessments. Using computational fluid dynamics (CFD) techniques, we have developed a method to quickly (

A Computational Model Quantifies the Effect of Anatomical Variability on Velopharyngeal Function

PubMed Central

Inouye, Joshua M.; Perry, Jamie L.; Lin, Kant Y.

2015-01-01

Purpose This study predicted the effects of velopharyngeal (VP) anatomical parameters on VP function to provide a greater understanding of speech mechanics and aid in the treatment of speech disorders. Method We created a computational model of the VP mechanism using dimensions obtained from magnetic resonance imaging measurements of 10 healthy adults. The model components included the levator veli palatini (LVP), the velum, and the posterior pharyngeal wall, and the simulations were based on material parameters from the literature. The outcome metrics were the VP closure force and LVP muscle activation required to achieve VP closure. Results Our average model compared favorably with experimental data from the literature. Simulations of 1,000 random anatomies reflected the large variability in closure forces observed experimentally. VP distance had the greatest effect on both outcome metrics when considering the observed anatomic variability. Other anatomical parameters were ranked by their predicted influences on the outcome metrics. Conclusions Our results support the implication that interventions for VP dysfunction that decrease anterior to posterior VP portal distance, increase velar length, and/or increase LVP cross-sectional area may be very effective. Future modeling studies will help to further our understanding of speech mechanics and optimize treatment of speech disorders. PMID:26049120

Visualization of stereoscopic anatomic models of the paranasal sinuses and cervical vertebrae from the surgical and procedural perspective.

PubMed

Chen, Jian; Smith, Andrew D; Khan, Majid A; Sinning, Allan R; Conway, Marianne L; Cui, Dongmei

2017-11-01

Recent improvements in three-dimensional (3D) virtual modeling software allows anatomists to generate high-resolution, visually appealing, colored, anatomical 3D models from computed tomography (CT) images. In this study, high-resolution CT images of a cadaver were used to develop clinically relevant anatomic models including facial skull, nasal cavity, septum, turbinates, paranasal sinuses, optic nerve, pituitary gland, carotid artery, cervical vertebrae, atlanto-axial joint, cervical spinal cord, cervical nerve root, and vertebral artery that can be used to teach clinical trainees (students, residents, and fellows) approaches for trans-sphenoidal pituitary surgery and cervical spine injection procedure. Volume, surface rendering and a new rendering technique, semi-auto-combined, were applied in the study. These models enable visualization, manipulation, and interaction on a computer and can be presented in a stereoscopic 3D virtual environment, which makes users feel as if they are inside the model. Anat Sci Educ 10: 598-606. © 2017 American Association of Anatomists. © 2017 American Association of Anatomists.

Comparisons of Computed Mobile Phone Induced SAR in the SAM Phantom to That in Anatomically Correct Models of the Human Head.

PubMed

Beard, Brian B; Kainz, Wolfgang; Onishi, Teruo; Iyama, Takahiro; Watanabe, Soichi; Fujiwara, Osamu; Wang, Jianqing; Bit-Babik, Giorgi; Faraone, Antonio; Wiart, Joe; Christ, Andreas; Kuster, Niels; Lee, Ae-Kyoung; Kroeze, Hugo; Siegbahn, Martin; Keshvari, Jafar; Abrishamkar, Houman; Simon, Winfried; Manteuffel, Dirk; Nikoloski, Neviana

2006-06-05

The specific absorption rates (SAR) determined computationally in the specific anthropomorphic mannequin (SAM) and anatomically correct models of the human head when exposed to a mobile phone model are compared as part of a study organized by IEEE Standards Coordinating Committee 34, SubCommittee 2, and Working Group 2, and carried out by an international task force comprising 14 government, academic, and industrial research institutions. The detailed study protocol defined the computational head and mobile phone models. The participants used different finite-difference time-domain software and independently positioned the mobile phone and head models in accordance with the protocol. The results show that when the pinna SAR is calculated separately from the head SAR, SAM produced a higher SAR in the head than the anatomically correct head models. Also the larger (adult) head produced a statistically significant higher peak SAR for both the 1- and 10-g averages than did the smaller (child) head for all conditions of frequency and position.

Mobile phone types and SAR characteristics of the human brain.

PubMed

Lee, Ae-Kyoung; Hong, Seon-Eui; Kwon, Jong-Hwa; Choi, Hyung-Do; Cardis, Elisabeth

2017-04-07

Mobile phones differ in terms of their operating frequency, outer shape, and form and location of the antennae, all of which affect the spatial distributions of their electromagnetic field and the level of electromagnetic absorption in the human head or brain. For this paper, the specific absorption rate (SAR) was calculated for four anatomical head models at different ages using 11 numerical phone models of different shapes and antenna configurations. The 11 models represent phone types accounting for around 86% of the approximately 1400 commercial phone models released into the Korean market since 2002. Seven of the phone models selected have an internal dual-band antenna, and the remaining four possess an external antenna. Each model was intended to generate an average absorption level equivalent to that of the same type of commercial phone model operating at the maximum available output power. The 1 g peak spatial SAR and ipsilateral and contralateral brain-averaged SARs were reported for all 11 phone models. The effects of the phone type, phone position, operating frequency, and age of head models on the brain SAR were comprehensively determined.

Mobile phone types and SAR characteristics of the human brain

NASA Astrophysics Data System (ADS)

Lee, Ae-Kyoung; Hong, Seon-Eui; Kwon, Jong-Hwa; Choi, Hyung-Do; Cardis, Elisabeth

2017-04-01

Mobile phones differ in terms of their operating frequency, outer shape, and form and location of the antennae, all of which affect the spatial distributions of their electromagnetic field and the level of electromagnetic absorption in the human head or brain. For this paper, the specific absorption rate (SAR) was calculated for four anatomical head models at different ages using 11 numerical phone models of different shapes and antenna configurations. The 11 models represent phone types accounting for around 86% of the approximately 1400 commercial phone models released into the Korean market since 2002. Seven of the phone models selected have an internal dual-band antenna, and the remaining four possess an external antenna. Each model was intended to generate an average absorption level equivalent to that of the same type of commercial phone model operating at the maximum available output power. The 1 g peak spatial SAR and ipsilateral and contralateral brain-averaged SARs were reported for all 11 phone models. The effects of the phone type, phone position, operating frequency, and age of head models on the brain SAR were comprehensively determined.

Representation and visualization of variability in a 3D anatomical atlas using the kidney as an example

NASA Astrophysics Data System (ADS)

Hacker, Silke; Handels, Heinz

2006-03-01

Computer-based 3D atlases allow an interactive exploration of the human body. However, in most cases such 3D atlases are derived from one single individual, and therefore do not regard the variability of anatomical structures concerning their shape and size. Since the geometric variability across humans plays an important role in many medical applications, our goal is to develop a framework of an anatomical atlas for representation and visualization of the variability of selected anatomical structures. The basis of the project presented is the VOXEL-MAN atlas of inner organs that was created from the Visible Human data set. For modeling anatomical shapes and their variability we utilize "m-reps" which allow a compact representation of anatomical objects on the basis of their skeletons. As an example we used a statistical model of the kidney that is based on 48 different variants. With the integration of a shape description into the VOXEL-MAN atlas it is now possible to query and visualize different shape variations of an organ, e.g. by specifying a person's age or gender. In addition to the representation of individual shape variants, the average shape of a population can be displayed. Besides a surface representation, a volume-based representation of the kidney's shape variants is also possible. It results from the deformation of the reference kidney of the volume-based model using the m-rep shape description. In this way a realistic visualization of the shape variants becomes possible, as well as the visualization of the organ's internal structures.

Model-based imaging of cardiac electrical function in human atria

NASA Astrophysics Data System (ADS)

Modre, Robert; Tilg, Bernhard; Fischer, Gerald; Hanser, Friedrich; Messnarz, Bernd; Schocke, Michael F. H.; Kremser, Christian; Hintringer, Florian; Roithinger, Franz

2003-05-01

Noninvasive imaging of electrical function in the human atria is attained by the combination of data from electrocardiographic (ECG) mapping and magnetic resonance imaging (MRI). An anatomical computer model of the individual patient is the basis for our computer-aided diagnosis of cardiac arrhythmias. Three patients suffering from Wolff-Parkinson-White syndrome, from paroxymal atrial fibrillation, and from atrial flutter underwent an electrophysiological study. After successful treatment of the cardiac arrhythmia with invasive catheter technique, pacing protocols with stimuli at several anatomical sites (coronary sinus, left and right pulmonary vein, posterior site of the right atrium, right atrial appendage) were performed. Reconstructed activation time (AT) maps were validated with catheter-based electroanatomical data, with invasively determined pacing sites, and with pacing at anatomical markers. The individual complex anatomical model of the atria of each patient in combination with a high-quality mesh optimization enables accurate AT imaging, resulting in a localization error for the estimated pacing sites within 1 cm. Our findings may have implications for imaging of atrial activity in patients with focal arrhythmias.

Gastrointestinal Dose-Histogram Effects in the Context of Dose-Volume–Constrained Prostate Radiation Therapy: Analysis of Data From the RADAR Prostate Radiation Therapy Trial

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ebert, Martin A., E-mail: Martin.Ebert@health.wa.gov.au; School of Physics, University of Western Australia, Perth, Western Australia; Foo, Kerwyn

Purpose: To use a high-quality multicenter trial dataset to determine dose-volume effects for gastrointestinal (GI) toxicity following radiation therapy for prostate carcinoma. Influential dose-volume histogram regions were to be determined as functions of dose, anatomical location, toxicity, and clinical endpoint. Methods and Materials: Planning datasets for 754 participants in the TROG 03.04 RADAR trial were available, with Late Effects of Normal Tissues (LENT) Subjective, Objective, Management, and Analytic (SOMA) toxicity assessment to a median of 72 months. A rank sum method was used to define dose-volume cut-points as near-continuous functions of dose to 3 GI anatomical regions, together with amore » comprehensive assessment of significance. Univariate and multivariate ordinal regression was used to assess the importance of cut-points at each dose. Results: Dose ranges providing significant cut-points tended to be consistent with those showing significant univariate regression odds-ratios (representing the probability of a unitary increase in toxicity grade per percent relative volume). Ranges of significant cut-points for rectal bleeding validated previously published results. Separation of the lower GI anatomy into complete anorectum, rectum, and anal canal showed the impact of mid-low doses to the anal canal on urgency and tenesmus, completeness of evacuation and stool frequency, and mid-high doses to the anorectum on bleeding and stool frequency. Derived multivariate models emphasized the importance of the high-dose region of the anorectum and rectum for rectal bleeding and mid- to low-dose regions for diarrhea and urgency and tenesmus, and low-to-mid doses to the anal canal for stool frequency, diarrhea, evacuation, and bleeding. Conclusions: Results confirm anatomical dependence of specific GI toxicities. They provide an atlas summarizing dose-histogram effects and derived constraints as functions of anatomical region, dose, toxicity, and endpoint for informing future radiation therapy planning.« less

An early colonisation pathway into northwest Australia 70-60,000 years ago

NASA Astrophysics Data System (ADS)

Norman, Kasih; Inglis, Josha; Clarkson, Chris; Faith, J. Tyler; Shulmeister, James; Harris, Daniel

2018-01-01

Colonisation of Sahul 70-60 thousand years ago (kya) represents the first great maritime migration undertaken by anatomically modern humans in one of the final phases of the Out of Africa dispersal. Visual connectivity network analyses, agent-based simulations and ocean current modelling reveal that modern humans could follow numerous northern and southern migration pathways into Sahul. Our results support a southern route out of Africa through South Asia with entry into ISEA through the Banda Arc, culminating in an early colonisation of Sahul on the northwest shelf. Our results show multiple colonisation events through other entry points were also probable, and raise interesting possibilities for complex regional migration and population histories.

Review and standardization of cell phone exposure calculations using the SAM phantom and anatomically correct head models.

PubMed

Beard, Brian B; Kainz, Wolfgang

2004-10-13

We reviewed articles using computational RF dosimetry to compare the Specific Anthropomorphic Mannequin (SAM) to anatomically correct models of the human head. Published conclusions based on such comparisons have varied widely. We looked for reasons that might cause apparently similar comparisons to produce dissimilar results. We also looked at the information needed to adequately compare the results of computational RF dosimetry studies. We concluded studies were not comparable because of differences in definitions, models, and methodology. Therefore we propose a protocol, developed by an IEEE standards group, as an initial step in alleviating this problem. The protocol calls for a benchmark validation study comparing the SAM phantom to two anatomically correct models of the human head. It also establishes common definitions and reporting requirements that will increase the comparability of all computational RF dosimetry studies of the human head.

Review and standardization of cell phone exposure calculations using the SAM phantom and anatomically correct head models

PubMed Central

Beard, Brian B; Kainz, Wolfgang

2004-01-01

We reviewed articles using computational RF dosimetry to compare the Specific Anthropomorphic Mannequin (SAM) to anatomically correct models of the human head. Published conclusions based on such comparisons have varied widely. We looked for reasons that might cause apparently similar comparisons to produce dissimilar results. We also looked at the information needed to adequately compare the results of computational RF dosimetry studies. We concluded studies were not comparable because of differences in definitions, models, and methodology. Therefore we propose a protocol, developed by an IEEE standards group, as an initial step in alleviating this problem. The protocol calls for a benchmark validation study comparing the SAM phantom to two anatomically correct models of the human head. It also establishes common definitions and reporting requirements that will increase the comparability of all computational RF dosimetry studies of the human head. PMID:15482601

Three dimensional printing technology and materials for treatment of elbow fractures.

PubMed

Yang, Long; Grottkau, Brian; He, Zhixu; Ye, Chuan

2017-11-01

3D printing is a rapid prototyping technology that uses a 3D digital model to physically build an object. The aim of this study was to evaluate the peri-operative effect of 3D printing in treating complex elbow fractures and its role in physician-patient communication and determine which material is best for surgical model printing. Forty patients with elbow fractures were randomly divided into a 3D printing-assisted surgery group (n = 20) and a conventional surgery group (n = 20). Surgery duration, intra-operative blood loss, anatomic reduction rate, incidence of complications and elbow function score were compared between the two groups. The printing parameters, the advantages and the disadvantages of PLA and ABS were also compared. The independent-samples t-test was used to compare the data between groups. A questionnaire was designed for orthopaedic surgeons to evaluate the verisimilitude, the appearance of being true or real, and effectiveness of the 3D printing fracture model. Another questionnaire was designed to evaluate physician-patient communication effectiveness. The 3D group showed shorter surgical duration, lower blood loss and higher elbow function score, compared with the conventional group. PLA is an environmentally friendly material, whereas ABS produce an odour in the printing process. Curling edges occurred easily in the printing process with ABS and were observed in four of ten ABS models but in only one PLA model. The overall scores given by the surgeons about the verisimilitude and effectiveness of the 3D model were relatively high. Patient satisfaction scores for the 3D model were higher than those for the 2D imaging data during physician-patient discussions. 3D-printed models can accurately depict the anatomic characteristics of fracture sites, help surgeons determine a surgical plan and represent an effective tool for physician-patient communication. PLA is more suitable for desktop fused deposition printing in surgical modeling applications.

Clavicle anatomical osteosynthesis plate breakage - failure analysis report based on patient morphological parameters.

PubMed

Marinescu, Rodica; Antoniac, Vasile Iulian; Stoia, Dan Ioan; Lăptoiu, Dan Constantin

2017-01-01

Clavicle fracture reported incidence is about 5% of fractures in adult; among them, those located in the middle third of the shaft represent more than 80% from the total of cases. Due to the special morphological and biomechanical constraints of the clavicle, several methods for restoring morphological integrity in these fractures are described, including conservative, non-surgical treatment. The last 10 years of clinical studies in the field have favored the surgical treatment for selected cases; several osteosynthesis implants are in use - mostly anatomical plates with specific advantages and documented complications. A failed anatomical clavicle plate was explanted and analyzed after a protocol using stereomicroscopy, scanning electron microscopy and energy dispersive spectrometry. Based on the computed tomography (CT) scan determination of patient morphological parameters, a finite elements analysis of the failure scenario was completed. The failure analysis has proved that the plate breakage had occurred in the point of maximal elastic stress and minor deformation. The clinical implication is that no hole should remain free of screw during clavicle plate fixation and the implant should be chosen based on patient morphological parameters. In comminuted clavicle fracture, anatomic bridging with locked plate technique may lead to implant failure due to increase of the stress in the midshaft area. Thorough knowledge of anatomy and morphology of complex bones like the clavicle is necessary. Modern osteosynthesis anatomical implants are still to be improved.

Functional brain networks reconstruction using group sparsity-regularized learning.

PubMed

Zhao, Qinghua; Li, Will X Y; Jiang, Xi; Lv, Jinglei; Lu, Jianfeng; Liu, Tianming

2018-06-01

Investigating functional brain networks and patterns using sparse representation of fMRI data has received significant interests in the neuroimaging community. It has been reported that sparse representation is effective in reconstructing concurrent and interactive functional brain networks. To date, most of data-driven network reconstruction approaches rarely take consideration of anatomical structures, which are the substrate of brain function. Furthermore, it has been rarely explored whether structured sparse representation with anatomical guidance could facilitate functional networks reconstruction. To address this problem, in this paper, we propose to reconstruct brain networks utilizing the structure guided group sparse regression (S2GSR) in which 116 anatomical regions from the AAL template, as prior knowledge, are employed to guide the network reconstruction when performing sparse representation of whole-brain fMRI data. Specifically, we extract fMRI signals from standard space aligned with the AAL template. Then by learning a global over-complete dictionary, with the learned dictionary as a set of features (regressors), the group structured regression employs anatomical structures as group information to regress whole brain signals. Finally, the decomposition coefficients matrix is mapped back to the brain volume to represent functional brain networks and patterns. We use the publicly available Human Connectome Project (HCP) Q1 dataset as the test bed, and the experimental results indicate that the proposed anatomically guided structure sparse representation is effective in reconstructing concurrent functional brain networks.

Renal mass anatomic characteristics and perioperative outcomes of laparoscopic partial nephrectomy: a critical analysis.

PubMed

Tsivian, Matvey; Ulusoy, Said; Abern, Michael; Wandel, Ayelet; Sidi, A Ami; Tsivian, Alexander

2012-10-01

Anatomic parameters determining renal mass complexity have been used in a number of proposed scoring systems despite lack of a critical analysis of their independent contributions. We sought to assess the independent contribution of anatomic parameters on perioperative outcomes of laparoscopic partial nephrectomy (LPN). Preoperative imaging studies were reviewed for 147 consecutive patients undergoing LPN for a single renal mass. Renal mass anatomy was recorded: Size, growth pattern (endo-/meso-/exophytic), centrality (central/hilar/peripheral), anterior/posterior, lateral/medial, polar location. Multivariable models were used to determine associations of anatomic parameters with warm ischemia time (WIT), operative time (OT), estimated blood loss (EBL), intra- and postoperative complications, as well as renal function. All models were adjusted for the learning curve and relevant confounders. Median (range) tumor size was 3.3 cm (1.5-11 cm); 52% were central and 14% hilar. While 44% were exophytic, 23% and 33% were mesophytic and endophytic, respectively. Anatomic parameters did not uniformly predict perioperative outcomes. WIT was associated with tumor size (P=0.068), centrality (central, P=0.016; hilar, P=0.073), and endophytic growth pattern (P=0.017). OT was only associated with tumor size (P<0.001). No anatomic parameter predicted EBL. Tumor centrality increased the odds of overall and intraoperative complications, without reaching statistical significance. Postoperative renal function was not associated with any of the anatomic parameters considered after adjustment for baseline function and WIT. Learning curve, considered as a confounder, was independently associated with reduced WIT and OT as well as reduced odds of intraoperative complications. This study provides a detailed analysis of the independent impact of renal mass anatomic parameters on perioperative outcomes. Our findings suggest diverse independent contributions of the anatomic parameters to the different measures of outcomes (WIT, OT, EBL, complications, and renal function) emphasizing the importance of the learning curve.

The Development of a Virtual 3D Model of the Renal Corpuscle from Serial Histological Sections for E-Learning Environments

ERIC Educational Resources Information Center

Roth, Jeremy A.; Wilson, Timothy D.; Sandig, Martin

2015-01-01

Histology is a core subject in the anatomical sciences where learners are challenged to interpret two-dimensional (2D) information (gained from histological sections) to extrapolate and understand the three-dimensional (3D) morphology of cells, tissues, and organs. In gross anatomical education 3D models and learning tools have been associated…

[The anatomy of a reduced skull model--visualisation of Leonardo da Vinci's anthropology].

PubMed

Ahner, E

2008-04-02

The article focuses on a rare example of a miniature skull of unknown origin. The profoundness of the anatomical details, conjoint with outstanding virtuosity, reminds of Leonardo da Vinci's anatomical skull studies and asks for additional interpretation beside the emblematic "memento mori"-character. Following the miscellaneous topics of his skull studies an anatomical-anthropological interpretation is proposed. For such a project the mergence of anthropology, history of medicine and history of art was mandatory. Concerning some discrepancies within the anatomical realism, the depiction of a pathology is discussed and beyond the visualisation of a historic concept of brain function.

Effects of Axial Torsion on Disc Height Distribution: an In Vivo Study

PubMed Central

Espinoza Orías, Alejandro A.; Mammoser, Nicole M.; Triano, John J.; An, Howard S.; Andersson, Gunnar B.J.; Inoue, Nozomu

2016-01-01

Objectives Axial rotation of the torso is commonly used during manipulation treatment of low back pain. Little is known about the effect of these positons on disc morphology. Rotation is a three-dimensional event that is inadequately represented with planar images in the clinic. True quantification of the intervertebral gap can be achieved with a disc height distribution. The objective of this study was to analyze disc height distribution patterns during torsion relevant to manipulation in vivo. Methods Eighty-one volunteers were CT-scanned both in supine and in right 50° rotation positions. Virtual models of each intervertebral gap representing the disc were created with the inferior endplate of each ‘disc’ set as the reference surface and separated into five anatomical zones: four peripheral and one central, corresponding to the footprint of the annulus fibrosus and nucleus pulposus, respectively. Whole-disc and individual anatomical zone disc height distributions were calculated in both positions, and were compared against each other with ANOVA, with significance set at p < 0.05. Results Mean neutral disc height was 7.32 (1.59) mm. With 50° rotation, a small but significant increase to 7.44 (1.52) mm (p < 0.0002) was observed. The right side showed larger separation in most levels, except at L5/S1. The posterior and right zones increased in height upon axial rotation of the spine (p < 0.0001), while the left, anterior and central decreased. Conclusions This study quantified important tensile/compressive changes disc height during torsion. The implications of these mutually opposing changes on spinal manipulation are still unknown. PMID:27059249

Evaluation of total knee mechanics using a crouching simulator with a synthetic knee substitute.

PubMed

Lowry, Michael; Rosenbaum, Heather; Walker, Peter S

2016-05-01

Mechanical evaluation of total knees is frequently required for aspects such as wear, strength, kinematics, contact areas, and force transmission. In order to carry out such tests, we developed a crouching simulator, based on the Oxford-type machine, with novel features including a synthetic knee including ligaments. The instrumentation and data processing methods enabled the determination of contact area locations and interface forces and moments, for a full flexion-extension cycle. To demonstrate the use of the simulator, we carried out a comparison of two different total knee designs, cruciate retaining and substituting. The first part of the study describes the simulator design and the methodology for testing the knees without requiring cadaveric knee specimens. The degrees of freedom of the anatomic hip and ankle joints were reproduced. Flexion-extension was obtained by changing quadriceps length, while variable hamstring forces were applied using springs. The knee joint was represented by three-dimensional printed blocks on to which the total knee components were fixed. Pretensioned elastomeric bands of realistic stiffnesses passed through holes in the block at anatomical locations to represent ligaments. Motion capture of the knees during flexion, together with laser scanning and computer modeling, was used to reconstruct contact areas on the bearing surfaces. A method was also developed for measuring tibial component interface forces and moments as a comparative assessment of fixation. The method involved interposing Tekscan pads at locations on the interface. Overall, the crouching machine and the methodology could be used for many different mechanical measurements of total knee designs, adapted especially for comparative or parametric studies. © IMechE 2016.

Electrocautery device does not provide adequate pulmonary vessel sealing in transumbilical anatomic pulmonary lobectomy.

PubMed

Liu, Hung-Ping; Chu, Yen; Wu, Yi-Cheng; Hsieh, Ming-Ju; Liu, Chieng-Ying; Chen, Tzu-Ping; Chao, Yin-Kai; Wu, Ching-Yang; Yeh, Chi-Ju; Ko, Po-Jen; Liu, Yun-Hen

2016-05-01

Safe pulmonary vessel sealing device plays a crucial role in anatomic lung resection. In 2014, we reported high rates of massive bleeding complications during transumbilical lobectomy in a canine model due to difficulty in managing the pulmonary vessel with an endostapler. In this animal survival series, we aimed to evaluate the outcome of pulmonary vessel sealing with an electrocautery device to simplify the transumbilical thoracic surgery. Under general anesthesia, a 3-cm longitudinal incision was made over the umbilicus. Under video guidance, a bronchoscope was inserted through the incision for exploration. The diaphragmatic wound was created with an electrocautery knife and used as the entrance into the thoracic cavity. Using the transumbilical technique, anatomic lobectomy was performed with electrosurgical devices and endoscopic vascular staplers in 15 canines. Transumbilical endoscopic anatomic lobectomy was successfully completed in 12 of the 15 animals. Intraoperative bleeding developed in three animals during pulmonary hilum dissection, where one animal was killed due to hemodynamic instability and the other two animals required thoracotomy to complete the operation. There were five delayed bleeding and surgical mortality cases caused by inadequate vessel sealing by electrosurgical devices. Postmortem examination confirmed correct transumbilical lobectomy in the twelve animals that survived the operations. Transumbilical anatomic lobectomy is technically feasible in a canine model; however, the electrosurgical devices were not effective in sealing the pulmonary vessel in the current canine model.

Hybrid computational phantoms representing the reference adult male and adult female: construction and applications for retrospective dosimetry.

PubMed

Hurtado, Jorge L; Lee, Choonsik; Lodwick, Daniel; Goede, Timothy; Williams, Jonathan L; Bolch, Wesley E

2012-03-01

Currently, two classes of computational phantoms have been developed for dosimetry calculation: (1) stylized (or mathematical) and (2) voxel (or tomographic) phantoms describing human anatomy through mathematical surface equations and 3D voxel matrices, respectively. Mathematical surface equations in stylized phantoms are flexible, but the resulting anatomy is not as realistic. Voxel phantoms display far better anatomical realism, but they are limited in terms of their ability to alter organ shape, position, and depth, as well as body posture. A new class of computational phantoms called hybrid phantoms takes advantage of the best features of stylized and voxel phantoms-flexibility and anatomical realism, respectively. In the current study, hybrid computational phantoms representing the adult male and female reference anatomy and anthropometry are presented. These phantoms serve as the starting framework for creating patient or worker sculpted whole-body phantoms for retrospective dose reconstruction. Contours of major organs and tissues were converted or segmented from computed tomography images of a 36-y-old Korean volunteer and a 25-y-old U.S. female patient, respectively, with supplemental high-resolution CT images of the cranium. Polygon mesh models for the major organs and tissues were reconstructed and imported into Rhinoceros™ for non-uniform rational B-spline (NURBS) surface modeling. The resulting NURBS/polygon mesh models representing body contour and internal anatomy were matched to anthropometric data and reference organ mass data provided by Centers for Disease Control and Prevention and International Commission on Radiation Protection, respectively. Finally, two hybrid adult male and female phantoms were completed where a total of eight anthropometric data categories were matched to standard values within 4% and organ volumes matched to ICRP data within 1% with the exception of total skin. The hybrid phantoms were voxelized from the NURBS phantoms at resolutions of 0.158 × 0.158 × 0.158 cm and 0.126 × 0.126 × 0.126 cm for the male and female, respectively. To highlight the flexibility of the hybrid phantoms, graphical displays are given of (1) underweight and overweight adult male phantoms, (2) a sitting position for the adult female phantom, and (3) extraction and higher-resolution voxelization of the small intestine for localized dosimetry of mucosal and stem cell layers. These phantoms are used to model radioactively contaminated individuals and to then assess time-dependent detector count rate thresholds corresponding to 50, 250, and 500 mSv effective dose, as might be needed during in-field radiological triage by first responders or first receivers.

Pediatric laryngeal simulator using 3D printed models: A novel technique.

PubMed

Kavanagh, Katherine R; Cote, Valerie; Tsui, Yvonne; Kudernatsch, Simon; Peterson, Donald R; Valdez, Tulio A

2017-04-01

Simulation to acquire and test technical skills is an essential component of medical education and residency training in both surgical and nonsurgical specialties. High-quality simulation education relies on the availability, accessibility, and reliability of models. The objective of this work was to describe a practical pediatric laryngeal model for use in otolaryngology residency training. Ideally, this model would be low-cost, have tactile properties resembling human tissue, and be reliably reproducible. Pediatric laryngeal models were developed using two manufacturing methods: direct three-dimensional (3D) printing of anatomical models and casted anatomical models using 3D-printed molds. Polylactic acid, acrylonitrile butadiene styrene, and high-impact polystyrene (HIPS) were used for the directly printed models, whereas a silicone elastomer (SE) was used for the casted models. The models were evaluated for anatomic quality, ease of manipulation, hardness, and cost of production. A tissue likeness scale was created to validate the simulation model. Fleiss' Kappa rating was performed to evaluate interrater agreement, and analysis of variance was performed to evaluate differences among the materials. The SE provided the most anatomically accurate models, with the tactile properties allowing for surgical manipulation of the larynx. Direct 3D printing was more cost-effective than the SE casting method but did not possess the material properties and tissue likeness necessary for surgical simulation. The SE models of the pediatric larynx created from a casting method demonstrated high quality anatomy, tactile properties comparable to human tissue, and easy manipulation with standard surgical instruments. Their use in a reliable, low-cost, accessible, modular simulation system provides a valuable training resource for otolaryngology residents. N/A. Laryngoscope, 127:E132-E137, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

[INCIDENCE AND SURGICAL IMPORTANCE OF PYRAMIDAL LOBE AND TUBERCLE OF THE THYROID GLAND: A PROSPECTIVE STUDY].

PubMed

Kovacić, Marijan; Kovadcić, Ivan

2015-01-01

The pyramidal lobe and tubercles are common anatomic variations of the thyroid gland, and their frequency is highly represented. While pyramidal lobe requires additional seriousness in identifying and its removal, especially in patients with hyperthyroidism and thyroid cancer, the presence of tubercles is desirable. Tubercle is covered by recurrent laryngeal nerve and directs the surgeon in his search and besides this, serves to facilitate detection of the upper parathyroid glands. In this prospective study we analysed 342 patients who underwent total thyroidectomy in the period from January 2009 to March 2015. We looked at the incidence and anatomic characteristics of pyramidal lobe and tubercles of the thyroid gland. The pyramidal lobe was present in 52.3% of the patients with more frequent central and left placement. Bilateral tubercles were present in 14.9%, while position right-sided phenomenon was represented in 39.5% and 18.5% in lower left (64.3% patients). Their prevalence by gender showed no significant difference (p = 0.59; p = 0.2). Associated presence of pyramidal lobe and tubercles on one or both sides is highly represented in our group of patients (34%), also with no differences by gender (p = 0.29). Length of the pyramidal lobe ranged from 1.3 to 4.7 cm (average 2.3 cm), and the size of tubercles in 36% of patients was over 1 cm. Recurrent laryngeal nerve was only in 1.8% placed laterally of tubercles, and the upper parathyroid gland in 95.4% was located above tubercle. Considering that only 16.5% of our patients did not have any of these anatomical variations, their presence during surgery is the rule, not the exception.

An Adaptive Complex Network Model for Brain Functional Networks

PubMed Central

Gomez Portillo, Ignacio J.; Gleiser, Pablo M.

2009-01-01

Brain functional networks are graph representations of activity in the brain, where the vertices represent anatomical regions and the edges their functional connectivity. These networks present a robust small world topological structure, characterized by highly integrated modules connected sparsely by long range links. Recent studies showed that other topological properties such as the degree distribution and the presence (or absence) of a hierarchical structure are not robust, and show different intriguing behaviors. In order to understand the basic ingredients necessary for the emergence of these complex network structures we present an adaptive complex network model for human brain functional networks. The microscopic units of the model are dynamical nodes that represent active regions of the brain, whose interaction gives rise to complex network structures. The links between the nodes are chosen following an adaptive algorithm that establishes connections between dynamical elements with similar internal states. We show that the model is able to describe topological characteristics of human brain networks obtained from functional magnetic resonance imaging studies. In particular, when the dynamical rules of the model allow for integrated processing over the entire network scale-free non-hierarchical networks with well defined communities emerge. On the other hand, when the dynamical rules restrict the information to a local neighborhood, communities cluster together into larger ones, giving rise to a hierarchical structure, with a truncated power law degree distribution. PMID:19738902

Accuracy and reliability of stitched cone-beam computed tomography images.

PubMed

Egbert, Nicholas; Cagna, David R; Ahuja, Swati; Wicks, Russell A

2015-03-01

This study was performed to evaluate the linear distance accuracy and reliability of stitched small field of view (FOV) cone-beam computed tomography (CBCT) reconstructed images for the fabrication of implant surgical guides. Three gutta percha points were fixed on the inferior border of a cadaveric mandible to serve as control reference points. Ten additional gutta percha points, representing fiduciary markers, were scattered on the buccal and lingual cortices at the level of the proposed complete denture flange. A digital caliper was used to measure the distance between the reference points and fiduciary markers, which represented the anatomic linear dimension. The mandible was scanned using small FOV CBCT, and the images were then reconstructed and stitched using the manufacturer's imaging software. The same measurements were then taken with the CBCT software. The anatomic linear dimension measurements and stitched small FOV CBCT measurements were statistically evaluated for linear accuracy. The mean difference between the anatomic linear dimension measurements and the stitched small FOV CBCT measurements was found to be 0.34 mm with a 95% confidence interval of +0.24 - +0.44 mm and a mean standard deviation of 0.30 mm. The difference between the control and the stitched small FOV CBCT measurements was insignificant within the parameters defined by this study. The proven accuracy of stitched small FOV CBCT data sets may allow image-guided fabrication of implant surgical stents from such data sets.

Multiple Antigenic Sites Are Involved in Blocking the Interaction of GII.4 Norovirus Capsid with ABH Histo-Blood Group Antigens

PubMed Central

Parra, Gabriel I.; Abente, Eugenio J.; Sandoval-Jaime, Carlos; Sosnovtsev, Stanislav V.; Bok, Karin

2012-01-01

Noroviruses are major etiological agents of acute viral gastroenteritis. In 2002, a GII.4 variant (Farmington Hills cluster) spread so rapidly in the human population that it predominated worldwide and displaced previous GII.4 strains. We developed and characterized a panel of six monoclonal antibodies (MAbs) directed against the capsid protein of a Farmington Hills-like GII.4 norovirus strain that was associated with a large hospital outbreak in Maryland in 2004. The six MAbs reacted with high titers against homologous virus-like particles (VLPs) by enzyme-linked immunoassay but did not react with denatured capsid protein in immunoblots. The expression and self-assembly of newly developed genogroup I/II chimeric VLPs showed that five MAbs bound to the GII.4 protruding (P) domain of the capsid protein, while one recognized the GII.4 shell (S) domain. Cross-competition assays and mutational analyses showed evidence for at least three distinct antigenic sites in the P domain and one in the S domain. MAbs that mapped to the P domain but not the S domain were able to block the interaction of VLPs with ABH histo-blood group antigens (HBGA), suggesting that multiple antigenic sites of the P domain are involved in HBGA blocking. Further analysis showed that two MAbs mapped to regions of the capsid that had been associated with the emergence of new GII.4 variants. Taken together, our data map antibody and HBGA carbohydrate binding to proximal regions of the norovirus capsid, showing that evolutionary pressures on the norovirus capsid protein may affect both antigenic and carbohydrate recognition phenotypes. PMID:22532688

Effect of Ethanolic Extract from Seeds or Pods of Xylopia Aethiopica (Dunal) A. Rich (Annonaceae) on the Testicular Function of Adult Male Rats.

PubMed

Abarikwu, Sunny O; Ogunlaja, Aemere; Otuechere, Chiagoziem A; Gideon, OlatunBosun

2017-10-01

Xylopia aethiopica (Annonaceae) is used in some folk medicines and widely consumed as a spice in some parts of Nigeria. Its efficacy as an anti-androgenic substance has warranted the attention of African scholars. This study evaluated the enzymatic activity of lactate dehydrogenase (LDH), γ-glutamyl transferase (γ-GT), sperm quality (motility, count, morphology), testosterone level and histo-pathological changes of the testis of rats chronically treated with ethanolic extract of the pods (without seeds), seeds, and fruits (pods + seeds) of Xylopia aethiopica. Male Wistar (224-246 g) rats were treated with the extract of the pods, seeds, and fruits of Xylopia aethiopica at the dose of 0, 50, 100, and 200 mg/kg body wt. for 60 days. Serum biochemistry, sperm quality and histo-pathological examination of the testis were assessed for any treatment-related adverse effects. After treatment with Xylopia aethiopica, testosterone level was decreased dose-dependently in the animals treated with the seed extract compared to all other groups. The enzymatic activities of LDH and γ-GT were higher in rats treated with the seed and fruit extracts compared with those treated with the pods. The numbers of motile sperm, and counts were decreased while the numbers of sperm with morphological defects were higher in rats treated with the seed and fruit extracts compared to the control. Histopathological changes of the testis were also more severe in rats treated with the highest dose of the seed extract. We conclude that the compounds related to the anti-infertility effects of Xylopia aethiopica are present in the seeds.

Structural insights into activation and inhibition of histo-aspartic protease (HAP) from Plasmodium falciparum

PubMed Central

Bhaumik, Prasenjit; Xiao, Huogen; Hidaka, Koushi; Gustchina, Alla; Kiso, Yoshiaki; Yada, Rickey Y.; Wlodawer, Alexander

2012-01-01

Histo-aspartic protease (HAP) from Plasmodium falciparum offers a promising target for the development of novel antimalarial drugs. HAP exhibits high sequence similarity to pepsin-like aspartic proteases, but one of the two catalytic aspartates, Asp32, is replaced by histidine. Crystal structures of the truncated zymogen of HAP and of the complex of the mature enzyme with inhibitor KNI-10395 have been determined at 2.1 and 2.5 Å resolution, respectively. As in other proplasmepsins, the propeptide of the zymogen interacts with the C-terminal domain of the enzyme, forcing the N- and C- terminal domains apart, thereby separating His32 and Asp215 and preventing formation of the mature active site. In the inhibitor complex the enzyme forms a tight domain-swapped dimer, not previously seen in any aspartic proteases. The inhibitor is found in an unprecedented conformation resembling the letter “U”, stabilized by two intramolecular hydrogen bonds. Surprisingly, the location and conformation of the inhibitor are similar to the fragment of helix 2 comprising residues 34p–38p in the prosegments of the zymogens of gastric aspartic proteases; a corresponding helix assumes a vastly different orientation in proplasmepsins. Each inhibitor molecule is in contact with two molecules of HAP, interacting with the carboxylate group of the catalytic Asp215 of one HAP protomer through a water molecule, while also making a direct hydrogen bond to Glu278A′ of the other protomer. A comparison of the shifts in the positions of the catalytic residues in the inhibitor complex presented here with those published previously gives further hints regarding the enzymatic mechanism of HAP. PMID:21928835

Structural Insights into the Activation and Inhibition of Histo-Aspartic Protease from Plasmodium falciparum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhaumik, Prasenjit; Xiao, Huogen; Hidaka, Koushi

2012-09-17

Histo-aspartic protease (HAP) from Plasmodium falciparum is a promising target for the development of novel antimalarial drugs. The sequence of HAP is highly similar to those of pepsin-like aspartic proteases, but one of the two catalytic aspartates, Asp32, is replaced with histidine. Crystal structures of the truncated zymogen of HAP and of the complex of the mature enzyme with inhibitor KNI-10395 have been determined at 2.1 and 2.5 {angstrom} resolution, respectively. As in other proplasmepsins, the propeptide of the zymogen interacts with the C-terminal domain of the enzyme, forcing the N- and C-terminal domains apart, thereby separating His32 and Asp215more » and preventing formation of the mature active site. In the inhibitor complex, the enzyme forms a tight domain-swapped dimer, not previously seen in any aspartic proteases. The inhibitor is found in an unprecedented conformation resembling the letter U, stabilized by two intramolecular hydrogen bonds. Surprisingly, the location and conformation of the inhibitor are similar to those of the fragment of helix 2 comprising residues 34p-38p in the prosegments of the zymogens of gastric aspartic proteases; a corresponding helix assumes a vastly different orientation in proplasmepsins. Each inhibitor molecule is in contact with two molecules of HAP, interacting with the carboxylate group of the catalytic Asp215 of one HAP protomer through a water molecule, while also making a direct hydrogen bond to Glu278A' of the other protomer. A comparison of the shifts in the positions of the catalytic residues in the inhibitor complex presented here with those published previously gives further hints regarding the enzymatic mechanism of HAP.« less

[Use of the CO2 laser in the treatment of pathologic changes in the vulva, vagina and uterine cervix].

PubMed

Stanimirović, B; Zivanović, Z; Popović-Lazić, J

1990-01-01

In the period from April 1987 to April 1990, 230 patients with pathological changes of the vulva, vagina and cervix uteri were treated with the CO2-laser. The diagnosis and pretreatment stages of the diseases were confirmed by the cytodiagnostic, colposcopic and histopathological results of the biophysics. In most cases, DNA-hybridization of human papilloma viruses confirmed their virus etiology. Twenty patients had peak condyloma of the vulva and vagina, 34 had benign cervical diseases, 65 were at the premalignant and 111 in the first stages of malignant cervical disease. Vaporizations, conical or cylindrical excisions were performed depending on the nature of disease and its localisation. The average age of operated patients was 30.6 years and the average parity 0.69. Operations were performed using analgesia and in rare cases total anesthesia. After the excision treatment, the tissue was checked histo-pathologically according to the principle of series. The complications were very rare. After operation, postoperative control was performed after 3.9 and 15 months, and later once a year. The results have shown that one treatment was sufficient in 80% of patients for curing vulvar and vaginal disease and 20% patients needed repeat because of the condyloma that relapsed. After the first treatment, benign and premalignant cervical diseases were cured in 100% of cases. In 95.4% operated patients at the first stages of cervical malignant diseases, the excisional treatment was final and in 4.6% needed an additional radical therapy because of a higher stage of lesion found by the conular histo-pathological analysis. There were no relapses relating to the cervix.

The importance of obstructive sleep apnoea and hypopnea pathophysiology for customized therapy.

PubMed

Bosi, Marcello; De Vito, Andrea; Gobbi, Riccardo; Poletti, Venerino; Vicini, Claudio

2017-03-01

The objective of this study is to highlight the importance of anatomical and not-anatomical factors' identification for customized therapy in OSAHS patients. The data sources are: MEDLINE, The Cochrane Library and EMBASE. A systematic review was performed to identify studies that analyze the role of multiple interacting factors involved in the OSAHS pathophysiology. 85 out of 1242 abstracts were selected for full-text review. A variable combinations pathophysiological factors contribute to realize differentiated OSAHS phenotypes: a small pharyngeal airway with a low resistance to collapse (increased critical closing pressure), an inadequate responses of pharyngeal dilator muscles (wakefulness drive to breathe), an unstable ventilator responsiveness to hypercapnia (high loop gain), and an increased propensity to wake related to upper airway obstruction (low arousal threshold). Identifying if the anatomical or not-anatomical factors are predominant in each OSAHS patient represents the current challenge in clinical practice, moreover for the treatment decision-making. In the future, if a reliable and accurate pathophysiological pattern for each OSAHS patient can be identified, a customized therapy will be feasible, with a significant improvement of surgical success in sleep surgery and a better understanding of surgical failure.

Metastatic pathways in patients with cutaneous melanoma.

PubMed

Adler, Nikki R; Haydon, Andrew; McLean, Catriona A; Kelly, John W; Mar, Victoria J

2017-01-01

Metastasis represents the end product of an elaborate biological process, which is determined by a complex interplay between metastatic tumour cells, host factors and homoeostatic mechanisms. Cutaneous melanoma can metastasize haematogenously or lymphogenously. The three predominant models that endeavour to explain the patterns of melanoma progression are the stepwise spread model, the simultaneous spread model and the model of differential spread. The time course to the development of metastases differs between the different metastatic routes. There are several clinical and histopathological risk factors for the different metastatic pathways. In particular, patient sex and the anatomical location of the primary tumour influence patterns of disease progression. There is limited existing evidence regarding the relationship between tumour mutation status, other diagnostic and prognostic biomarkers and the metastatic pathways of primary cutaneous melanoma. This knowledge gap needs to be addressed to better identify patients at high risk of disease recurrence and personalize surveillance strategies. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Semi-Automated Trajectory Analysis of Deep Ballistic Penetrating Brain Injury

PubMed Central

Folio, Les; Solomon, Jeffrey; Biassou, Nadia; Fischer, Tatjana; Dworzak, Jenny; Raymont, Vanessa; Sinaii, Ninet; Wassermann, Eric M.; Grafman, Jordan

2016-01-01

Background Penetrating head injuries (PHIs) are common in combat operations and most have visible wound paths on computed tomography (CT). Objective We assess agreement between an automated trajectory analysis-based assessment of brain injury and manual tracings of encephalomalacia on CT. Methods We analyzed 80 head CTs with ballistic PHI from the Institutional Review Board approved Vietnam head injury registry. Anatomic reports were generated from spatial coordinates of projectile entrance and terminal fragment location. These were compared to manual tracings of the regions of encephalomalacia. Dice’s similarity coefficients, kappa, sensitivities, and specificities were calculated to assess agreement. Times required for case analysis were also compared. Results Results show high specificity of anatomic regions identified on CT with semiautomated anatomical estimates and manual tracings of tissue damage. Radiologist’s and medical students’ anatomic region reports were similar (Kappa 0.8, t-test p < 0.001). Region of probable injury modeling of involved brain structures was sensitive (0.7) and specific (0.9) compared with manually traced structures. Semiautomated analysis was 9-fold faster than manual tracings. Conclusion Our region of probable injury spatial model approximates anatomical regions of encephalomalacia from ballistic PHI with time-saving over manual methods. Results show potential for automated anatomical reporting as an adjunct to current practice of radiologist/neurosurgical review of brain injury by penetrating projectiles. PMID:23707123

How spatial abilities and dynamic visualizations interplay when learning functional anatomy with 3D anatomical models.

PubMed

Berney, Sandra; Bétrancourt, Mireille; Molinari, Gaëlle; Hoyek, Nady

2015-01-01

The emergence of dynamic visualizations of three-dimensional (3D) models in anatomy curricula may be an adequate solution for spatial difficulties encountered with traditional static learning, as they provide direct visualization of change throughout the viewpoints. However, little research has explored the interplay between learning material presentation formats, spatial abilities, and anatomical tasks. First, to understand the cognitive challenges a novice learner would be faced with when first exposed to 3D anatomical content, a six-step cognitive task analysis was developed. Following this, an experimental study was conducted to explore how presentation formats (dynamic vs. static visualizations) support learning of functional anatomy, and affect subsequent anatomical tasks derived from the cognitive task analysis. A second aim was to investigate the interplay between spatial abilities (spatial visualization and spatial relation) and presentation formats when the functional anatomy of a 3D scapula and the associated shoulder flexion movement are learned. Findings showed no main effect of the presentation formats on performances, but revealed the predictive influence of spatial visualization and spatial relation abilities on performance. However, an interesting interaction between presentation formats and spatial relation ability for a specific anatomical task was found. This result highlighted the influence of presentation formats when spatial abilities are involved as well as the differentiated influence of spatial abilities on anatomical tasks. © 2015 American Association of Anatomists.

An ontology-based comparative anatomy information system

PubMed Central

Travillian, Ravensara S.; Diatchka, Kremena; Judge, Tejinder K.; Wilamowska, Katarzyna; Shapiro, Linda G.

2010-01-01

Introduction This paper describes the design, implementation, and potential use of a comparative anatomy information system (CAIS) for querying on similarities and differences between homologous anatomical structures across species, the knowledge base it operates upon, the method it uses for determining the answers to the queries, and the user interface it employs to present the results. The relevant informatics contributions of our work include (1) the development and application of the structural difference method, a formalism for symbolically representing anatomical similarities and differences across species; (2) the design of the structure of a mapping between the anatomical models of two different species and its application to information about specific structures in humans, mice, and rats; and (3) the design of the internal syntax and semantics of the query language. These contributions provide the foundation for the development of a working system that allows users to submit queries about the similarities and differences between mouse, rat, and human anatomy; delivers result sets that describe those similarities and differences in symbolic terms; and serves as a prototype for the extension of the knowledge base to any number of species. Additionally, we expanded the domain knowledge by identifying medically relevant structural questions for the human, the mouse, and the rat, and made an initial foray into the validation of the application and its content by means of user questionnaires, software testing, and other feedback. Methods The anatomical structures of the species to be compared, as well as the mappings between species, are modeled on templates from the Foundational Model of Anatomy knowledge base, and compared using graph-matching techniques. A graphical user interface allows users to issue queries that retrieve information concerning similarities and differences between structures in the species being examined. Queries from diverse information sources, including domain experts, peer-reviewed articles, and reference books, have been used to test the system and to illustrate its potential use in comparative anatomy studies. Results 157 test queries were submitted to the CAIS system, and all of them were correctly answered. The interface was evaluated in terms of clarity and ease of use. This testing determined that the application works well, and is fairly intuitive to use, but users want to see more clarification of the meaning of the different types of possible queries. Some of the interface issues will naturally be resolved as we refine our conceptual model to deal with partial and complex homologies in the content. Conclusions The CAIS system and its associated methods are expected to be useful to biologists and translational medicine researchers. Possible applications range from supporting theoretical work in clarifying and modeling ontogenetic, physiological, pathological, and evolutionary transformations, to concrete techniques for improving the analysis of genotype–phenotype relationships among various animal models in support of a wide array of clinical and scientific initiatives. PMID:21146377

Development of a novel ex vivo porcine laparoscopic Heller myotomy and Nissen fundoplication training model (Toronto lap-Nissen simulator).

PubMed

Ujiie, Hideki; Kato, Tatsuya; Hu, Hsin-Pei; Bauer, Patrycja; Patel, Priya; Wada, Hironobu; Lee, Daiyoon; Fujino, Kosuke; Schieman, Colin; Pierre, Andrew; Waddell, Thomas K; Keshavjee, Shaf; Darling, Gail E; Yasufuku, Kazuhiro

2017-06-01

Surgical trainees are required to develop competency in a variety of laparoscopic operations. Developing laparoscopic technical skills can be difficult as there has been a decrease in the number of procedures performed. This study aims to develop an inexpensive and anatomically relevant model for training in laparoscopic foregut procedures. An ex vivo , anatomic model of the human upper abdomen was developed using intact porcine esophagus, stomach, diaphragm and spleen. The Toronto lap-Nissen simulator was contained in a laparoscopic box-trainer and included an arch system to simulate the normal radial shape and tension of the diaphragm. We integrated the use of this training model as a part of our laparoscopic skills laboratory-training curriculum. Afterwards, we surveyed trainees to evaluate the observed benefit of the learning session. Twenty-five trainees and five faculty members completed a survey regarding the use of this model. Among the trainees, only 4 (16%) had experience with laparoscopic Heller myotomy and Nissen fundoplication. They reported that practicing with the model was a valuable use of their limited time, repeating the exercise would be of additional benefit, and that the exercise improved their ability to perform or assist in an actual case in the operating room. Significant improvements were found in the following subjective measures comparing pre- vs. post-training: (I) knowledge level (5.6 vs. 8.0, P<0.001); (II) comfort level in assisting (6.3 vs. 7.6, P<0.001); and (III) comfort level in performing as the primary surgeon (4.9 vs. 7.1, P<0.001). The trainees and faculty members agreed that this model was of adequate fidelity and was a representative simulation of actual human anatomy. We developed an easily reproducible training model for laparoscopic procedures. This simulator reproduces human anatomy and increases the trainees' comfort level in performing and assisting with myotomy and fundoplication.

Development of a novel ex vivo porcine laparoscopic Heller myotomy and Nissen fundoplication training model (Toronto lap-Nissen simulator)

PubMed Central

Ujiie, Hideki; Kato, Tatsuya; Hu, Hsin-Pei; Bauer, Patrycja; Patel, Priya; Wada, Hironobu; Lee, Daiyoon; Fujino, Kosuke; Schieman, Colin; Pierre, Andrew; Waddell, Thomas K.; Keshavjee, Shaf; Darling, Gail E.

2017-01-01

Background Surgical trainees are required to develop competency in a variety of laparoscopic operations. Developing laparoscopic technical skills can be difficult as there has been a decrease in the number of procedures performed. This study aims to develop an inexpensive and anatomically relevant model for training in laparoscopic foregut procedures. Methods An ex vivo, anatomic model of the human upper abdomen was developed using intact porcine esophagus, stomach, diaphragm and spleen. The Toronto lap-Nissen simulator was contained in a laparoscopic box-trainer and included an arch system to simulate the normal radial shape and tension of the diaphragm. We integrated the use of this training model as a part of our laparoscopic skills laboratory-training curriculum. Afterwards, we surveyed trainees to evaluate the observed benefit of the learning session. Results Twenty-five trainees and five faculty members completed a survey regarding the use of this model. Among the trainees, only 4 (16%) had experience with laparoscopic Heller myotomy and Nissen fundoplication. They reported that practicing with the model was a valuable use of their limited time, repeating the exercise would be of additional benefit, and that the exercise improved their ability to perform or assist in an actual case in the operating room. Significant improvements were found in the following subjective measures comparing pre- vs. post-training: (I) knowledge level (5.6 vs. 8.0, P<0.001); (II) comfort level in assisting (6.3 vs. 7.6, P<0.001); and (III) comfort level in performing as the primary surgeon (4.9 vs. 7.1, P<0.001). The trainees and faculty members agreed that this model was of adequate fidelity and was a representative simulation of actual human anatomy. Conclusions We developed an easily reproducible training model for laparoscopic procedures. This simulator reproduces human anatomy and increases the trainees’ comfort level in performing and assisting with myotomy and fundoplication. PMID:28740664

Effects of fluid structure interaction in a three dimensional model of the spinal subarachnoid space.

PubMed

Cheng, Shaokoon; Fletcher, David; Hemley, Sarah; Stoodley, Marcus; Bilston, Lynne

2014-08-22

It is unknown whether spinal cord motion has a significant effect on cerebrospinal fluid (CSF) pressure and therefore the importance of including fluid structure interaction (FSI) in computational fluid dynamics models (CFD) of the spinal subarachnoid space (SAS) is unclear. This study aims to determine the effects of FSI on CSF pressure and spinal cord motion in a normal and in a stenosis model of the SAS. A three-dimensional patient specific model of the SAS and spinal cord were constructed from MR anatomical images and CSF flow rate measurements obtained from a healthy human being. The area of SAS at spinal level T4 was constricted by 20% to represent the stenosis model. FSI simulations in both models were performed by running ANSYS CFX and ANSYS Mechanical in tandem. Results from this study show that the effect of FSI on CSF pressure is only about 1% in both the normal and stenosis models and therefore show that FSI has a negligible effect on CSF pressure. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Scaled Anatomical Model Creation of Biomedical Tomographic Imaging Data and Associated Labels for Subsequent Sub-surface Laser Engraving (SSLE) of Glass Crystals.

PubMed

Betts, Aislinn M; McGoldrick, Matthew T; Dethlefs, Christopher R; Piotrowicz, Justin; Van Avermaete, Tony; Maki, Jeff; Gerstler, Steve; Leevy, W M

2017-04-25

Biomedical imaging modalities like computed tomography (CT) and magnetic resonance (MR) provide excellent platforms for collecting three-dimensional data sets of patient or specimen anatomy in clinical or preclinical settings. However, the use of a virtual, on-screen display limits the ability of these tomographic images to fully convey the anatomical information embedded within. One solution is to interface a biomedical imaging data set with 3D printing technology to generate a physical replica. Here we detail a complementary method to visualize tomographic imaging data with a hand-held model: Sub Surface Laser Engraving (SSLE) of crystal glass. SSLE offers several unique benefits including: the facile ability to include anatomical labels, as well as a scale bar; streamlined multipart assembly of complex structures in one medium; high resolution in the X, Y, and Z planes; and semi-transparent shells for visualization of internal anatomical substructures. Here we demonstrate the process of SSLE with CT data sets derived from pre-clinical and clinical sources. This protocol will serve as a powerful and inexpensive new tool with which to visualize complex anatomical structures for scientists and students in a number of educational and research settings.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Guo Qiang; Luo, Lingyun; Ogbuji, Chime

The interaction of multiple types of relationships among anatomical classes in the Foundational Model of Anatomy (FMA) can provide inferred information valuable for quality assurance. This paper introduces a method called Motif Checking (MOCH) to study the effects of such multi-relation type interactions. MOCH represents patterns of multitype interaction as small labeled sub-graph motifs, whose nodes represent class variables, and labeled edges represent relational types. By representing FMA as an RDF graph and motifs as SPARQL queries, fragments of FMA are automatically obtained as auditing candidates. Leveraging the scalability and reconfigurability of Semantic Web Technology (OWL, RDF and SPARQL) andmore » Virtuoso, we performed exhaustive analyses of three 2-node motifs, resulting in 638 matching FMA configurations; twelve 3-node motifs, resulting in 202,960 configurations. Using the Principal Ideal Explorer (PIE) methodology as an extension of MOCH, we were able to identify 755 root nodes with 4,100 respective descendants with opposing antonyms in their class names for arbitrary-length motifs. With possible disjointness implied by antonyms, we performed manual inspection of a subset of the resulting FMA fragments and tracked down a source of abnormal inferred conclusions (captured by the motifs), coming from a gender-neutral class being modeled as a part of gender-specific class, such as “Urinary system” is a part of “Female human body.” Our results demonstrate that MOCH and PIE provide a unique source of valuable information for quality assurance. Since our approach is general, it is applicable to any ontological system with an OWL representation.« less

Tele-Immersion: Preferred Infrastructure for Anatomy Instruction

ERIC Educational Resources Information Center

Silverstein, Jonathan C.; Ehrenfeld, Jesse M.; Croft, Darin A.; Dech, Fred W.; Small, Stephen; Cook, Sandy

2006-01-01

Understanding spatial relationships among anatomic structures is an essential skill for physicians. Traditional medical education--using books, lectures, physical models, and cadavers--may be insufficient for teaching complex anatomical relationships. This study was designed to measure whether teaching complex anatomy to medical students using…

Gastrointestinal stromal tumors: the histology report.

PubMed

Dei Tos, Angelo P; Laurino, Licia; Bearzi, Italo; Messerini, Luca; Farinati, Fabio

2011-03-01

Gastrointestinal stromal tumors (GISTs) represent a mesenchymal neoplasm occurring primarily in the gastrointestinal tract, and showing differentiation toward the interstitial cell of Cajal. Its incidence is approximately 15 case/100,000/year. Stomach and small bowel are the most frequently affected anatomic sites. GIST represents a morphological, immunophenotypical and molecular distinct entity, the recognition of which has profound therapeutic implications. In fact, they have shown an exquisite sensitivity to treatment with the tyrosine kinase inhibitor imatinib. Diagnosis relies upon morphology along with immunodetection of KIT and/or DOG1. When dealing with KIT negative cases, molecular analysis of KIT/PDGFRA genes may help in confirming diagnosis. Molecular evaluation of both genes are in any case recommended as mutational status provides key predictive information. Pathologists also play a key role in providing an estimation of the risk of biological aggressiveness, which is currently based on anatomic location of the tumor, size, and mitotic activity. Copyright © 2011 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd.. All rights reserved.

Use of Intraoperative Computed Tomography for Revisional Procedures in Patients with Complex Maxillofacial Trauma

PubMed Central

Singh, Mansher; Ricci, Joseph A.

2015-01-01

Background: In patients with panfacial fractures and distorted anatomic landmarks of zygomatic and orbital complex, there is a risk of zygomaticomaxillary complex (ZMC) malpositioning even with the best efforts for surgical repair. This results in increased number of additional procedures to achieve accurate positioning. Methods: We describe the usage of intraoperative C-arm cone-beam computed tomographic (CT) scan for ZMC malpositioning in a representative patient with panfacial fractures. Results: We have successfully used intraoperative CT scan for ZMC malpositioning in 3 patients. The representative patient had ZMC malposition after the initial attempt of surgical repair without any intraoperative imaging. On using intraoperative CT scan during the next attempt, we were able to reposition the ZMC accurately. Conclusions: Intraoperative CT scan might improve the accuracy of ZMC positioning and decrease the chances of potential additional surgeries. In patients with distorted anatomical landmarks and panfacial fractures, it can be especially helpful toward correcting ZMC malposition. PMID:26301152

Augmented Reality Guidance for the Resection of Missing Colorectal Liver Metastases: An Initial Experience.

PubMed

Ntourakis, Dimitrios; Memeo, Ricardo; Soler, Luc; Marescaux, Jacques; Mutter, Didier; Pessaux, Patrick

2016-02-01

Modern chemotherapy achieves the shrinking of colorectal cancer liver metastases (CRLM) to such extent that they may disappear from radiological imaging. Disappearing CRLM rarely represents a complete pathological remission and have an important risk of recurrence. Augmented reality (AR) consists in the fusion of real-time patient images with a computer-generated 3D virtual patient model created from pre-operative medical imaging. The aim of this prospective pilot study is to investigate the potential of AR navigation as a tool to help locate and surgically resect missing CRLM. A 3D virtual anatomical model was created from thoracoabdominal CT-scans using customary software (VR RENDER(®), IRCAD). The virtual model was superimposed to the operative field using an Exoscope (VITOM(®), Karl Storz, Tüttlingen, Germany). Virtual and real images were manually registered in real-time using a video mixer, based on external anatomical landmarks with an estimated accuracy of 5 mm. This modality was tested in three patients, with four missing CRLM that had sizes from 12 to 24 mm, undergoing laparotomy after receiving pre-operative oxaliplatin-based chemotherapy. AR display and fine registration was performed within 6 min. AR helped detect all four missing CRLM, and guided their resection. In all cases the planned security margin of 1 cm was clear and resections were confirmed to be R0 by pathology. There was no postoperative major morbidity or mortality. No local recurrence occurred in the follow-up period of 6-22 months. This initial experience suggests that AR may be a helpful navigation tool for the resection of missing CRLM.

De Sedibus et Causis Morborum: is Essential Tremor a Primary Disease of the Cerebellum?

PubMed

Louis, Elan D

2016-06-01

Morgagni's 1761 publication of De sedibus et causis morborum (i.e., of the Seats and Causes of Diseases) represented a paradigmatic moment in the history of medicine. The book ushered in a new way of conceptualizing human disease, shattering old dogma, and linking constellations of symptoms and signs (i.e., clinical disease) with anatomic pathology in specific organs (i.e., organ disease). This was the anatomical-clinical method, and it attempted to unveil "the seat" of each disease in a specific organ. Essential tremor (ET) is among the most common neurological diseases. There is little debate that the origin of ET lies in the brain, but if one tries to delve more deeply than this, things become murky. The dogma for the past 40 years has been that the seat of ET is the inferior olivary nucleus. Closer scrutiny of this model, however, has revealed its many flaws, and the model, based on little if any empiric evidence, has increasingly lost favor. Arising from a wealth of research in recent years is a growing body of knowledge that links ET to a disarrangement of the cerebellum. Data from a variety of sources reviewed in this issue (clinical, neuroimaging, neurochemical, animal model, physiological, and pathological) link ET to the cerebellum. That the cerebellum is involved in an abnormal brain loop that is responsible for ET is not debated. The tantalizing question is whether an abnormality in the cerebellum is the prime mover, and whether the cerebellum is the seat of this particular disease.

Anatomical parameterization for volumetric meshing of the liver

NASA Astrophysics Data System (ADS)

Vera, Sergio; González Ballester, Miguel A.; Gil, Debora

2014-03-01

A coordinate system describing the interior of organs is a powerful tool for a systematic localization of injured tissue. If the same coordinate values are assigned to specific anatomical landmarks, the coordinate system allows integration of data across different medical image modalities. Harmonic mappings have been used to produce parametric coordinate systems over the surface of anatomical shapes, given their flexibility to set values at specific locations through boundary conditions. However, most of the existing implementations in medical imaging restrict to either anatomical surfaces, or the depth coordinate with boundary conditions is given at sites of limited geometric diversity. In this paper we present a method for anatomical volumetric parameterization that extends current harmonic parameterizations to the interior anatomy using information provided by the volume medial surface. We have applied the methodology to define a common reference system for the liver shape and functional anatomy. This reference system sets a solid base for creating anatomical models of the patient's liver, and allows comparing livers from several patients in a common framework of reference.

The Anatomical and Functional Organization of the Human Visual Pulvinar

PubMed Central

Pinsk, Mark A.; Kastner, Sabine

2015-01-01

The pulvinar is the largest nucleus in the primate thalamus and contains extensive, reciprocal connections with visual cortex. Although the anatomical and functional organization of the pulvinar has been extensively studied in old and new world monkeys, little is known about the organization of the human pulvinar. Using high-resolution functional magnetic resonance imaging at 3 T, we identified two visual field maps within the ventral pulvinar, referred to as vPul1 and vPul2. Both maps contain an inversion of contralateral visual space with the upper visual field represented ventrally and the lower visual field represented dorsally. vPul1 and vPul2 border each other at the vertical meridian and share a representation of foveal space with iso-eccentricity lines extending across areal borders. Additional, coarse representations of contralateral visual space were identified within ventral medial and dorsal lateral portions of the pulvinar. Connectivity analyses on functional and diffusion imaging data revealed a strong distinction in thalamocortical connectivity between the dorsal and ventral pulvinar. The two maps in the ventral pulvinar were most strongly connected with early and extrastriate visual areas. Given the shared eccentricity representation and similarity in cortical connectivity, we propose that these two maps form a distinct visual field map cluster and perform related functions. The dorsal pulvinar was most strongly connected with parietal and frontal areas. The functional and anatomical organization observed within the human pulvinar was similar to the organization of the pulvinar in other primate species. SIGNIFICANCE STATEMENT The anatomical organization and basic response properties of the visual pulvinar have been extensively studied in nonhuman primates. Yet, relatively little is known about the functional and anatomical organization of the human pulvinar. Using neuroimaging, we found multiple representations of visual space within the ventral human pulvinar and extensive topographically organized connectivity with visual cortex. This organization is similar to other nonhuman primates and provides additional support that the general organization of the pulvinar is consistent across the primate phylogenetic tree. These results suggest that the human pulvinar, like other primates, is well positioned to regulate corticocortical communication. PMID:26156987

Interactive lesion segmentation on dynamic contrast enhanced breast MRI using a Markov model

NASA Astrophysics Data System (ADS)

Wu, Qiu; Salganicoff, Marcos; Krishnan, Arun; Fussell, Donald S.; Markey, Mia K.

2006-03-01

The purpose of this study is to develop a method for segmenting lesions on Dynamic Contrast-Enhanced (DCE) breast MRI. DCE breast MRI, in which the breast is imaged before, during, and after the administration of a contrast agent, enables a truly 3D examination of breast tissues. This functional angiogenic imaging technique provides noninvasive assessment of microcirculatory characteristics of tissues in addition to traditional anatomical structure information. Since morphological features and kinetic curves from segmented lesions are to be used for diagnosis and treatment decisions, lesion segmentation is a key pre-processing step for classification. In our study, the ROI is defined by a bounding box containing the enhancement region in the subtraction image, which is generated by subtracting the pre-contrast image from 1st post-contrast image. A maximum a posteriori (MAP) estimate of the class membership (lesion vs. non-lesion) for each voxel is obtained using the Iterative Conditional Mode (ICM) method. The prior distribution of the class membership is modeled as a multi-level logistic model, a Markov Random Field model in which the class membership of each voxel is assumed to depend upon its nearest neighbors only. The likelihood distribution is assumed to be Gaussian. The parameters of each Gaussian distribution are estimated from a dozen voxels manually selected as representative of the class. The experimental segmentation results demonstrate anatomically plausible breast tissue segmentation and the predicted class membership of voxels from the interactive segmentation algorithm agrees with the manual classifications made by inspection of the kinetic enhancement curves. The proposed method is advantageous in that it is efficient, flexible, and robust.

Dose conversion coefficients based on the Chinese mathematical phantom and MCNP code for external photon irradiation.

PubMed

Qiu, Rui; Li, Junli; Zhang, Zhan; Liu, Liye; Bi, Lei; Ren, Li

2009-02-01

A set of conversion coefficients from kerma free-in-air to the organ-absorbed dose are presented for external monoenergetic photon beams from 10 keV to 10 MeV based on the Chinese mathematical phantom, a whole-body mathematical phantom model. The model was developed based on the methods of the Oak Ridge National Laboratory mathematical phantom series and data from the Chinese Reference Man and the Reference Asian Man. This work is carried out to obtain the conversion coefficients based on this model, which represents the characteristics of the Chinese population, as the anatomical parameters of the Chinese are different from those of Caucasians. Monte Carlo simulation with MCNP code is carried out to calculate the organ dose conversion coefficients. Before the calculation, the effects from the physics model and tally type are investigated, considering both the calculation efficiency and precision. In the calculation irradiation conditions include anterior-posterior, posterior-anterior, right lateral, left lateral, rotational and isotropic geometries. Conversion coefficients from this study are compared with those recommended in the Publication 74 of International Commission on Radiological Protection (ICRP74) since both the sets of data are calculated with mathematical phantoms. Overall, consistency between the two sets of data is observed and the difference for more than 60% of the data is below 10%. However, significant deviations are also found, mainly for the superficial organs (up to 65.9%) and bone surface (up to 66%). The big difference of the dose conversion coefficients for the superficial organs at high photon energy could be ascribed to kerma approximation for the data in ICRP74. Both anatomical variations between races and the calculation method contribute to the difference of the data for bone surface.

Correlated gene expression and anatomical communication support synchronized brain activity in the mouse functional connectome.

PubMed

Mills, Brian D; Grayson, David S; Shunmugavel, Anandakumar; Miranda-Dominguez, Oscar; Feczko, Eric; Earl, Eric; Neve, Kim; Fair, Damien A

2018-05-22

Cognition and behavior depend on synchronized intrinsic brain activity that is organized into functional networks across the brain. Research has investigated how anatomical connectivity both shapes and is shaped by these networks, but not how anatomical connectivity interacts with intra-areal molecular properties to drive functional connectivity. Here, we present a novel linear model to explain functional connectivity by integrating systematically obtained measurements of axonal connectivity, gene expression, and resting state functional connectivity MRI in the mouse brain. The model suggests that functional connectivity arises from both anatomical links and inter-areal similarities in gene expression. By estimating these effects, we identify anatomical modules in which correlated gene expression and anatomical connectivity support functional connectivity. Along with providing evidence that not all genes equally contribute to functional connectivity, this research establishes new insights regarding the biological underpinnings of coordinated brain activity measured by BOLD fMRI. SIGNIFICANCE STATEMENT Efforts at characterizing the functional connectome with fMRI have risen exponentially over the last decade. Yet despite this rise, the biological underpinnings of these functional measurements are still largely unknown. The current report begins to fill this void by investigating the molecular underpinnings of the functional connectome through an integration of systematically obtained structural information and gene expression data throughout the rodent brain. We find that both white matter connectivity and similarity in regional gene expression relate to resting state functional connectivity. The current report furthers our understanding of the biological underpinnings of the functional connectome and provides a linear model that can be utilized to streamline preclinical animal studies of disease. Copyright © 2018 the authors.

Anatomical Entity Recognition with a Hierarchical Framework Augmented by External Resources

PubMed Central

Xu, Yan; Hua, Ji; Ni, Zhaoheng; Chen, Qinlang; Fan, Yubo; Ananiadou, Sophia; Chang, Eric I-Chao; Tsujii, Junichi

2014-01-01

References to anatomical entities in medical records consist not only of explicit references to anatomical locations, but also other diverse types of expressions, such as specific diseases, clinical tests, clinical treatments, which constitute implicit references to anatomical entities. In order to identify these implicit anatomical entities, we propose a hierarchical framework, in which two layers of named entity recognizers (NERs) work in a cooperative manner. Each of the NERs is implemented using the Conditional Random Fields (CRF) model, which use a range of external resources to generate features. We constructed a dictionary of anatomical entity expressions by exploiting four existing resources, i.e., UMLS, MeSH, RadLex and BodyPart3D, and supplemented information from two external knowledge bases, i.e., Wikipedia and WordNet, to improve inference of anatomical entities from implicit expressions. Experiments conducted on 300 discharge summaries showed a micro-averaged performance of 0.8509 Precision, 0.7796 Recall and 0.8137 F1 for explicit anatomical entity recognition, and 0.8695 Precision, 0.6893 Recall and 0.7690 F1 for implicit anatomical entity recognition. The use of the hierarchical framework, which combines the recognition of named entities of various types (diseases, clinical tests, treatments) with information embedded in external knowledge bases, resulted in a 5.08% increment in F1. The resources constructed for this research will be made publicly available. PMID:25343498

Can virtual reality improve anatomy education? A randomised controlled study of a computer-generated three-dimensional anatomical ear model.

PubMed

Nicholson, Daren T; Chalk, Colin; Funnell, W Robert J; Daniel, Sam J

2006-11-01

The use of computer-generated 3-dimensional (3-D) anatomical models to teach anatomy has proliferated. However, there is little evidence that these models are educationally effective. The purpose of this study was to test the educational effectiveness of a computer-generated 3-D model of the middle and inner ear. We reconstructed a fully interactive model of the middle and inner ear from a magnetic resonance imaging scan of a human cadaver ear. To test the model's educational usefulness, we conducted a randomised controlled study in which 28 medical students completed a Web-based tutorial on ear anatomy that included the interactive model, while a control group of 29 students took the tutorial without exposure to the model. At the end of the tutorials, both groups were asked a series of 15 quiz questions to evaluate their knowledge of 3-D relationships within the ear. The intervention group's mean score on the quiz was 83%, while that of the control group was 65%. This difference in means was highly significant (P < 0.001). Our findings stand in contrast to the handful of previous randomised controlled trials that evaluated the effects of computer-generated 3-D anatomical models on learning. The equivocal and negative results of these previous studies may be due to the limitations of these studies (such as small sample size) as well as the limitations of the models that were studied (such as a lack of full interactivity). Given our positive results, we believe that further research is warranted concerning the educational effectiveness of computer-generated anatomical models.

The diagnosis of the cause of the death of Venerina.

PubMed

Mazzotti, Giovanni; Falconi, Mirella; Teti, Gabriella; Zago, Michela; Lanari, Marcello; Manzoli, Francesco A

2010-02-01

Venerina (little Venus) is the name given to a wax model representing a pregnant young woman that was created in Florence (Italy) by Clemente Susini (1754-1814) in 1782. It is currently located in the historic Science Museum of the University of Bologna. The model was constructed so as to enable removal of the thoracic and abdominal walls and various organs, exposing the heart, diaphragm and an opened uterus with a well-developed fetus. The woman is small, about 145 cm (4' 9') tall and of delicate build; she looks like a teenage girl. We know that Clemente Susini worked directly with the cadaver and copied the anatomical preparation exactly. This artist often represented the true structure using a wax mould; the existence of two other versions of this specimen suggests that this model was made in this way. Therefore, Venerina's body may be a faithful representation of a young woman who died while pregnant. Observation of the body confirms that the organs are normal, except for the heart and great vessels. The walls of both ventricles are of equal thickness and the ventricles themselves of approximately equal size. The arch of the aorta and the enlarged pulmonary trunk are connected by a short duct about 3.5 mm in diameter. If this structure represents an open arterial duct, we can deduce that the two ventricles worked under the same conditions of blood pressure, hence their equal wall thickness. If the young woman died from this congenital disease, the cause of death has been diagnosed on a wax model of her body after more than two centuries.

The esophagiome: integrated anatomical, mechanical, and physiological analysis of the esophago-gastric segment.

PubMed

Zhao, Jingbo; McMahon, Barry; Fox, Mark; Gregersen, Hans

2018-06-10

Esophageal diseases are highly prevalent and carry significant socioeconomic burden. Despite the apparently simple function of the esophagus, we still struggle to better understand its physiology and pathophysiology. The assessment of large data sets and application of multiscale mathematical organ models have gained attention as part of the Physiome Project. This has long been recognized in cardiology but has only recently gained attention for the gastrointestinal(GI) tract. The term "esophagiome" implies a holistic assessment of esophageal function, from cellular and muscle physiology to the mechanical responses that transport and mix fluid contents. These anatomical, mechanical, and physiological models underlie the development of a "virtual esophagus" modeling framework to characterize and analyze function and disease. Functional models incorporate anatomical details with sensory-motor responses, especially related to biomechanical functions such as bolus transport. Our review builds on previous reviews and focuses on assessment of detailed anatomical and geometric data using advanced imaging technology for evaluation of gastro-esophageal reflux disease (GERD), and on esophageal mechanophysiology assessed using technologies that distend the esophagus. Integration of mechanics- and physiology-based analysis is a useful characteristic of the esophagiome. Experimental data on pressures and geometric characteristics are useful for the validation of mathematical and computer models of the esophagus that may provide predictions of novel endoscopic, surgical, and pharmaceutical treatment options. © 2018 New York Academy of Sciences.

The UF family of reference hybrid phantoms for computational radiation dosimetry

NASA Astrophysics Data System (ADS)

Lee, Choonsik; Lodwick, Daniel; Hurtado, Jorge; Pafundi, Deanna; Williams, Jonathan L.; Bolch, Wesley E.

2010-01-01

Computational human phantoms are computer models used to obtain dose distributions within the human body exposed to internal or external radiation sources. In addition, they are increasingly used to develop detector efficiencies for in vivo whole-body counters. Two classes of computational human phantoms have been widely utilized for dosimetry calculation: stylized and voxel phantoms that describe human anatomy through mathematical surface equations and 3D voxel matrices, respectively. Stylized phantoms are flexible in that changes to organ position and shape are possible given avoidance of region overlap, while voxel phantoms are typically fixed to a given patient anatomy, yet can be proportionally scaled to match individuals of larger or smaller stature, but of equivalent organ anatomy. Voxel phantoms provide much better anatomical realism as compared to stylized phantoms which are intrinsically limited by mathematical surface equations. To address the drawbacks of these phantoms, hybrid phantoms based on non-uniform rational B-spline (NURBS) surfaces have been introduced wherein anthropomorphic flexibility and anatomic realism are both preserved. Researchers at the University of Florida have introduced a series of hybrid phantoms representing the ICRP Publication 89 reference newborn, 15 year, and adult male and female. In this study, six additional phantoms are added to the UF family of hybrid phantoms—those of the reference 1 year, 5 year and 10 year child. Head and torso CT images of patients whose ages were close to the targeted ages were obtained under approved protocols. Major organs and tissues were segmented from these images using an image processing software, 3D-DOCTOR™. NURBS and polygon mesh surfaces were then used to model individual organs and tissues after importing the segmented organ models to the 3D NURBS modeling software, Rhinoceros™. The phantoms were matched to four reference datasets: (1) standard anthropometric data, (2) reference organ masses from ICRP Publication 89, (3) reference elemental compositions provided in ICRP 89 as well as ICRU Report 46, and (4) reference data on the alimentary tract organs given in ICRP Publications 89 and 100. Various adjustments and refinements to the organ systems of the previously described newborn, 15 year and adult phantoms are also presented. The UF series of hybrid phantoms retain the non-uniform scalability of stylized phantoms while maintaining the anatomical realism of patient-specific voxel phantoms with respect to organ shape, depth and inter-organ distance. While the final versions of these phantoms are in a voxelized format for radiation transport simulation, their primary format is given as NURBS and polygon mesh surfaces, thus permitting one to sculpt non-reference phantoms using the reference phantoms as an anatomic template.

The development of a population of 4D pediatric XCAT phantoms for imaging research and optimization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Segars, W. P., E-mail: paul.segars@duke.edu; Norris, Hannah; Sturgeon, Gregory M.

Purpose: We previously developed a set of highly detailed 4D reference pediatric extended cardiac-torso (XCAT) phantoms at ages of newborn, 1, 5, 10, and 15 yr with organ and tissue masses matched to ICRP Publication 89 values. In this work, we extended this reference set to a series of 64 pediatric phantoms of varying age and height and body mass percentiles representative of the public at large. The models will provide a library of pediatric phantoms for optimizing pediatric imaging protocols. Methods: High resolution positron emission tomography-computed tomography data obtained from the Duke University database were reviewed by a practicingmore » experienced radiologist for anatomic regularity. The CT portion of the data was then segmented with manual and semiautomatic methods to form a target model defined using nonuniform rational B-spline surfaces. A multichannel large deformation diffeomorphic metric mapping algorithm was used to calculate the transform from the best age matching pediatric XCAT reference phantom to the patient target. The transform was used to complete the target, filling in the nonsegmented structures and defining models for the cardiac and respiratory motions. The complete phantoms, consisting of thousands of structures, were then manually inspected for anatomical accuracy. The mass for each major tissue was calculated and compared to linearly interpolated ICRP values for different ages. Results: Sixty four new pediatric phantoms were created in this manner. Each model contains the same level of detail as the original XCAT reference phantoms and also includes parameterized models for the cardiac and respiratory motions. For the phantoms that were 10 yr old and younger, we included both sets of reproductive organs. This gave them the capability to simulate both male and female anatomy. With this, the population can be expanded to 92. Wide anatomical variation was clearly seen amongst the phantom models, both in organ shape and size, even for models of the same age and sex. The phantoms can be combined with existing simulation packages to generate realistic pediatric imaging data from different modalities. Conclusions: This work provides a large cohort of highly detailed pediatric phantoms with 4D capabilities of varying age, height, and body mass. The population of phantoms will provide a vital tool with which to optimize 3D and 4D pediatric imaging devices and techniques in terms of image quality and radiation-absorbed dose.« less

ABCD classification system: a novel classification for subaxial cervical spine injuries.

PubMed

Shousha, Mootaz

2014-04-20

The classification system was derived through a retrospective analysis of 73 consecutive cases of subaxial cervical spine injury as well as thorough literature review. To define a new classification system for subaxial cervical spine injuries. There exist several methods to classify subaxial cervical spine injuries but no single system has emerged as clearly superior to the others. On the basis of a 2-column anatomical model, the first part of the proposed classification is an anatomical description of the injury. It delivers the information whether the injury is bony, ligamentous, or a combined one. The first 4 alphabetical letters have been used for simplicity. Each column is represented by an alphabetical letter from A to D. Each letter has a radiological meaning (A = Absent injury, B = Bony lesion, C = Combined bony and ligamentous, D = Disc or ligamentous injury).The second part of the classification is represented by 3 modifiers. These are the neurological status of the patient (N), the degree of spinal canal stenosis (S), and the degree of instability (I). For simplicity, each modifier was graded in an ascending pattern of severity from zero to 2. The last part is optional and denotes which radiological examination has been used to define the injury type. The new ABCD classification was applicable for all patients. The most common type was anterior ligamentous and posterior combined injury "DC" (37.9%), followed by "DD" injury in 12% of the cases. Through this work a new classification for cervical spine injuries is proposed. The aim is to establish criteria for a common language in description of cervical injuries aiming for simplification, especially for junior residents. Each letter and each sign has a meaning to deliver the largest amount of information. Both the radiological as well as the clinical data are represented in this scheme. However, further evaluation of this classification is needed. 3.

Human Brain Modeling with Its Anatomical Structure and Realistic Material Properties for Brain Injury Prediction.

PubMed

Atsumi, Noritoshi; Nakahira, Yuko; Tanaka, Eiichi; Iwamoto, Masami

2018-05-01

Impairments of executive brain function after traumatic brain injury (TBI) due to head impacts in traffic accidents need to be obviated. Finite element (FE) analyses with a human brain model facilitate understanding of the TBI mechanisms. However, conventional brain FE models do not suitably describe the anatomical structure in the deep brain, which is a critical region for executive brain function, and the material properties of brain parenchyma. In this study, for better TBI prediction, a novel brain FE model with anatomical structure in the deep brain was developed. The developed model comprises a constitutive model of brain parenchyma considering anisotropy and strain rate dependency. Validation was performed against postmortem human subject test data associated with brain deformation during head impact. Brain injury analyses were performed using head acceleration curves obtained from reconstruction analysis of rear-end collision with a human whole-body FE model. The difference in structure was found to affect the regions of strain concentration, while the difference in material model contributed to the peak strain value. The injury prediction result by the proposed model was consistent with the characteristics in the neuroimaging data of TBI patients due to traffic accidents.

The effect of anatomic variations of circle of Willis on cerebral blood distribution during posture change from supination to standing: a model study.

PubMed

Zhang, Chi; Li, Shuyu; Pu, Fang; Fan, Yubo; Li, Deyu

2014-01-01

The anatomic variation of Circle of Willis (CoW) has great impact on its compensatory capacity during stroke and cerebral ischemia. In the present study, a series of lumped parameter models were developed and used to simulate the effect of postural changes on the cerebral blood flow in ICA stenosis patients with different anatomic variants of the CoW. The results showed that the asymmetric distribution of cerebral blood flow caused by stenosis was attenuated in standing position in complete and half-complete CoW. However, in incomplete CoW, the decrease in blood flow in the ipsilateral cerebral arteries caused by unilateral ICA stenosis was dramatic in both supine and standing positions, a likely result of inadequate collateral circulation within the CoW. In conclusion, the anatomic variation of CoW plays a significant role in maintaining the balance of cerebral blood supply in patients with ICA stenosis, especially during postural change.

Pregnant woman and road safety: experimental crash test with post mortem human subject.

PubMed

Delotte, Jerome; Behr, Michel; Thollon, Lionel; Arnoux, Pierre-Jean; Baque, Patrick; Bongain, Andre; Brunet, Christian

2008-05-01

Trauma affect between 3 and 7% of all pregnancies in industrialized countries, and the leading cause of these traumas is car crashes. The difficulty to appreciate physiologic and anatomic changes occurring during pregnancy explain that majority of studies were not based on anatomical data. We present a protocol to create a realistic anatomical model of pregnant woman using a post mortem human subject (PMHS). We inserted a physical model of the gravid uterus into the pelvis of a PMHS. 3D acceleration sensors were placed on the subject to measure the acceleration on different body segments. We simulated three frontal impact situations at 20 km/h between two average European cars. Two main kinematics events were identified as possible causes of injuries: lap belt loading and backrest impact. Cadaver experiments provide one interesting complementary approach to study injury mechanisms related to road accidents involving pregnant women. This anatomical accuracy makes it possible to progress in the field of safety devices.

Do 3D Printing Models Improve Anatomical Teaching About Hepatic Segments to Medical Students? A Randomized Controlled Study.

PubMed

Kong, Xiangxue; Nie, Lanying; Zhang, Huijian; Wang, Zhanglin; Ye, Qiang; Tang, Lei; Huang, Wenhua; Li, Jianyi

2016-08-01

It is a difficult and frustrating task for young surgeons and medical students to understand the anatomy of hepatic segments. We tried to develop an optimal 3D printing model of hepatic segments as a teaching aid to improve the teaching of hepatic segments. A fresh human cadaveric liver without hepatic disease was CT scanned. After 3D reconstruction, three types of 3D computer models of hepatic structures were designed and 3D printed as models of hepatic segments without parenchyma (type 1) and with transparent parenchyma (type 2), and hepatic ducts with segmental partitions (type 3). These models were evaluated by six experts using a five-point Likert scale. Ninety two medical freshmen were randomized into four groups to learn hepatic segments with the aid of the three types of models and traditional anatomic atlas (TAA). Their results of two quizzes were compared to evaluate the teaching effects of the four methods. Three types of models were successful produced which displayed the structures of hepatic segments. By experts' evaluation, type 3 model was better than type 1 and 2 models in anatomical condition, type 2 and 3 models were better than type 1 model in tactility, and type 3 model was better than type 1 model in overall satisfaction (P < 0.05). The first quiz revealed that type 1 model was better than type 2 model and TAA, while type 3 model was better than type 2 and TAA in teaching effects (P < 0.05). The second quiz found that type 1 model was better than TAA, while type 3 model was better than type 2 model and TAA regarding teaching effects (P < 0.05). Only TAA group had significant declines between two quizzes (P < 0.05). The model with segmental partitions proves to be optimal, because it can best improve anatomical teaching about hepatic segments.

The role of photorespiration during the evolution of C4 photosynthesis in the genus Flaveria

PubMed Central

Mallmann, Julia; Heckmann, David; Bräutigam, Andrea; Lercher, Martin J; Weber, Andreas PM; Westhoff, Peter; Gowik, Udo

2014-01-01

C4 photosynthesis represents a most remarkable case of convergent evolution of a complex trait, which includes the reprogramming of the expression patterns of thousands of genes. Anatomical, physiological, and phylogenetic and analyses as well as computational modeling indicate that the establishment of a photorespiratory carbon pump (termed C2 photosynthesis) is a prerequisite for the evolution of C4. However, a mechanistic model explaining the tight connection between the evolution of C4 and C2 photosynthesis is currently lacking. Here we address this question through comparative transcriptomic and biochemical analyses of closely related C3, C3–C4, and C4 species, combined with Flux Balance Analysis constrained through a mechanistic model of carbon fixation. We show that C2 photosynthesis creates a misbalance in nitrogen metabolism between bundle sheath and mesophyll cells. Rebalancing nitrogen metabolism requires anaplerotic reactions that resemble at least parts of a basic C4 cycle. Our findings thus show how C2 photosynthesis represents a pre-adaptation for the C4 system, where the evolution of the C2 system establishes important C4 components as a side effect. DOI: http://dx.doi.org/10.7554/eLife.02478.001 PMID:24935935

Generating Facial Expressions Using an Anatomically Accurate Biomechanical Model.

PubMed

Wu, Tim; Hung, Alice; Mithraratne, Kumar

2014-11-01

This paper presents a computational framework for modelling the biomechanics of human facial expressions. A detailed high-order (Cubic-Hermite) finite element model of the human head was constructed using anatomical data segmented from magnetic resonance images. The model includes a superficial soft-tissue continuum consisting of skin, the subcutaneous layer and the superficial Musculo-Aponeurotic system. Embedded within this continuum mesh, are 20 pairs of facial muscles which drive facial expressions. These muscles were treated as transversely-isotropic and their anatomical geometries and fibre orientations were accurately depicted. In order to capture the relative composition of muscles and fat, material heterogeneity was also introduced into the model. Complex contact interactions between the lips, eyelids, and between superficial soft tissue continuum and deep rigid skeletal bones were also computed. In addition, this paper investigates the impact of incorporating material heterogeneity and contact interactions, which are often neglected in similar studies. Four facial expressions were simulated using the developed model and the results were compared with surface data obtained from a 3D structured-light scanner. Predicted expressions showed good agreement with the experimental data.

Use of laser 3D surface digitizer in data collection and 3D modeling of anatomical structures

NASA Astrophysics Data System (ADS)

Tse, Kelly; Van Der Wall, Hans; Vu, Dzung H.

2006-02-01

A laser digitizer (Konica-Minolta Vivid 910) is used to obtain 3-dimensional surface scans of anatomical structures with a maximum resolution of 0.1mm. Placing the specimen on a turntable allows multiple scans allaround because the scanner only captures data from the portion facing its lens. A computer model is generated using 3D modeling software such as Geomagic. The 3D model can be manipulated on screen for repeated analysis of anatomical features, a useful capability when the specimens are rare or inaccessible (museum collection, fossils, imprints in rock formation.). As accurate measurements can be performed on the computer model, instead of taking measurements on actual specimens only at the archeological excavation site e.g., a variety of quantitative data can be later obtained on the computer model in the laboratory as new ideas come to mind. Our group had used a mechanical contact digitizer (Microscribe) for this purpose, but with the surface digitizer, we have been obtaining data sets more accurately and more quickly.

Comparisons of Computed Mobile Phone Induced SAR in the SAM Phantom to That in Anatomically Correct Models of the Human Head

PubMed Central

Beard, Brian B.; Kainz, Wolfgang; Onishi, Teruo; Iyama, Takahiro; Watanabe, Soichi; Fujiwara, Osamu; Wang, Jianqing; Bit-Babik, Giorgi; Faraone, Antonio; Wiart, Joe; Christ, Andreas; Kuster, Niels; Lee, Ae-Kyoung; Kroeze, Hugo; Siegbahn, Martin; Keshvari, Jafar; Abrishamkar, Houman; Simon, Winfried; Manteuffel, Dirk; Nikoloski, Neviana

2018-01-01

The specific absorption rates (SAR) determined computationally in the specific anthropomorphic mannequin (SAM) and anatomically correct models of the human head when exposed to a mobile phone model are compared as part of a study organized by IEEE Standards Coordinating Committee 34, SubCommittee 2, and Working Group 2, and carried out by an international task force comprising 14 government, academic, and industrial research institutions. The detailed study protocol defined the computational head and mobile phone models. The participants used different finite-difference time-domain software and independently positioned the mobile phone and head models in accordance with the protocol. The results show that when the pinna SAR is calculated separately from the head SAR, SAM produced a higher SAR in the head than the anatomically correct head models. Also the larger (adult) head produced a statistically significant higher peak SAR for both the 1- and 10-g averages than did the smaller (child) head for all conditions of frequency and position. PMID:29515260

Creation of 3D Multi-Body Orthodontic Models by Using Independent Imaging Sensors

PubMed Central

Barone, Sandro; Paoli, Alessandro; Razionale, Armando Viviano

2013-01-01

In the field of dental health care, plaster models combined with 2D radiographs are widely used in clinical practice for orthodontic diagnoses. However, complex malocclusions can be better analyzed by exploiting 3D digital dental models, which allow virtual simulations and treatment planning processes. In this paper, dental data captured by independent imaging sensors are fused to create multi-body orthodontic models composed of teeth, oral soft tissues and alveolar bone structures. The methodology is based on integrating Cone-Beam Computed Tomography (CBCT) and surface structured light scanning. The optical scanner is used to reconstruct tooth crowns and soft tissues (visible surfaces) through the digitalization of both patients' mouth impressions and plaster casts. These data are also used to guide the segmentation of internal dental tissues by processing CBCT data sets. The 3D individual dental tissues obtained by the optical scanner and the CBCT sensor are fused within multi-body orthodontic models without human supervisions to identify target anatomical structures. The final multi-body models represent valuable virtual platforms to clinical diagnostic and treatment planning. PMID:23385416

Creation of 3D multi-body orthodontic models by using independent imaging sensors.

PubMed

Barone, Sandro; Paoli, Alessandro; Razionale, Armando Viviano

2013-02-05

In the field of dental health care, plaster models combined with 2D radiographs are widely used in clinical practice for orthodontic diagnoses. However, complex malocclusions can be better analyzed by exploiting 3D digital dental models, which allow virtual simulations and treatment planning processes. In this paper, dental data captured by independent imaging sensors are fused to create multi-body orthodontic models composed of teeth, oral soft tissues and alveolar bone structures. The methodology is based on integrating Cone-Beam Computed Tomography (CBCT) and surface structured light scanning. The optical scanner is used to reconstruct tooth crowns and soft tissues (visible surfaces) through the digitalization of both patients' mouth impressions and plaster casts. These data are also used to guide the segmentation of internal dental tissues by processing CBCT data sets. The 3D individual dental tissues obtained by the optical scanner and the CBCT sensor are fused within multi-body orthodontic models without human supervisions to identify target anatomical structures. The final multi-body models represent valuable virtual platforms to clinical diagnostic and treatment planning.

Modeling Single Ventricle Physiology: Review of Engineering Tools to Study First Stage Palliation of Hypoplastic Left Heart Syndrome

PubMed Central

Biglino, Giovanni; Giardini, Alessandro; Hsia, Tain-Yen; Figliola, Richard; Taylor, Andrew M.; Schievano, Silvia

2013-01-01

First stage palliation of hypoplastic left heart syndrome, i.e., the Norwood operation, results in a complex physiological arrangement, involving different shunting options (modified Blalock-Taussig, RV-PA conduit, central shunt from the ascending aorta) and enlargement of the hypoplastic ascending aorta. Engineering techniques, both computational and experimental, can aid in the understanding of the Norwood physiology and their correct implementation can potentially lead to refinement of the decision-making process, by means of patient-specific simulations. This paper presents some of the available tools that can corroborate clinical evidence by providing detailed insight into the fluid dynamics of the Norwood circulation as well as alternative surgical scenarios (i.e., virtual surgery). Patient-specific anatomies can be manufactured by means of rapid prototyping and such models can be inserted in experimental set-ups (mock circulatory loops) that can provide a valuable source of validation data as well as hydrodynamic information. Such models can be tuned to respond to differing the patient physiologies. Experimental set-ups can also be compatible with visualization techniques, like particle image velocimetry and cardiovascular magnetic resonance, further adding to the knowledge of the local fluid dynamics. Multi-scale computational models include detailed three-dimensional (3D) anatomical information coupled to a lumped parameter network representing the remainder of the circulation. These models output both overall hemodynamic parameters while also enabling to investigate the local fluid dynamics of the aortic arch or the shunt. As an alternative, pure lumped parameter models can also be employed to model Stage 1 palliation, taking advantage of a much lower computational cost, albeit missing the 3D anatomical component. Finally, analytical techniques, such as wave intensity analysis, can be employed to study the Norwood physiology, providing a mechanistic perspective on the ventriculo-arterial coupling for this specific surgical scenario. PMID:24400277

Deformable adult human phantoms for radiation protection dosimetry: anthropometric data representing size distributions of adult worker populations and software algorithms

NASA Astrophysics Data System (ADS)

Hum Na, Yong; Zhang, Binquan; Zhang, Juying; Caracappa, Peter F.; Xu, X. George

2010-07-01

Computational phantoms representing workers and patients are essential in estimating organ doses from various occupational radiation exposures and medical procedures. Nearly all existing phantoms, however, were purposely designed to match internal and external anatomical features of the Reference Man as defined by the International Commission on Radiological Protection (ICRP). To reduce uncertainty in dose calculations caused by anatomical variations, a new generation of phantoms of varying organ and body sizes is needed. This paper presents detailed anatomical data in tables and graphs that are used to design such size-adjustable phantoms representing a range of adult individuals in terms of the body height, body weight and internal organ volume/mass. Two different sets of information are used to derive the phantom sets: (1) individual internal organ size and volume/mass distribution data derived from the recommendations of the ICRP in Publications 23 and 89 and (2) whole-body height and weight percentile data from the National Health and Nutrition Examination Survey (NHANES 1999-2002). The NHANES height and weight data for 19 year old males and females are used to estimate the distributions of individuals' size, which is unknown, that corresponds to the ICRP organ and tissue distributions. This paper then demonstrates the usage of these anthropometric data in the development of deformable anatomical phantoms. A pair of phantoms—modeled entirely in mesh surfaces—of the adult male and female, RPI-adult male (AM) and RPI-adult female (AF) are used as the base for size-adjustable phantoms. To create percentile-specific phantoms from these two base phantoms, organ surface boundaries are carefully altered according to the tabulated anthropometric data. Software algorithms are developed to automatically match the organ volumes and masses with desired values. Finally, these mesh-based, percentile-specific phantoms are converted into voxel-based phantoms for Monte Carlo radiation transport simulations. This paper also compares absorbed organ doses for the RPI-AM-5th-height and -weight percentile phantom (165 cm in height and 56 kg in weight) and the RPI-AM-95th-height and -weight percentile phantom (188 cm in height and 110 kg in weight) with those for the RPI-AM-50th-height and -weight percentile phantom (176 cm in height and 73 kg in weight) from exposures to 0.5 MeV external photon beams. The results suggest a general finding that the phantoms representing a slimmer and shorter individual male received higher absorbed organ doses because of lesser degree of photon attenuation due to smaller amount of body fat. In particular, doses to the prostate and adrenal in the RPI-AM-5th-height and -weight percentile phantom is about 10% greater than those in the RPI-AM-50th-height and -weight percentile phantom approximating the ICRP Reference Man. On the other hand, the doses to the prostate and adrenal in the RPI-AM-95th-height and -weight percentile phantom are approximately 20% greater than those in the RPI-AM-50th-height and -weight percentile phantom. Although this study only considered the photon radiation of limited energies and irradiation geometries, the potential to improve the organ dose accuracy using the deformable phantom technology is clearly demonstrated.

Deformable adult human phantoms for radiation protection dosimetry: anthropometric data representing size distributions of adult worker populations and software algorithms

PubMed Central

Na, Yong Hum; Zhang, Binquan; Zhang, Juying; Caracappa, Peter F; Xu, X George

2012-01-01

Computational phantoms representing workers and patients are essential in estimating organ doses from various occupational radiation exposures and medical procedures. Nearly all existing phantoms, however, were purposely designed to match internal and external anatomical features of the Reference Man as defined by the International Commission on Radiological Protection (ICRP). To reduce uncertainty in dose calculations caused by anatomical variations, a new generation of phantoms of varying organ and body sizes is needed. This paper presents detailed anatomical data in tables and graphs that are used to design such size-adjustable phantoms representing a range of adult individuals in terms of the body height, body weight and internal organ volume/mass. Two different sets of information are used to derive the phantom sets: (1) individual internal organ size and volume/mass distribution data derived from the recommendations of the ICRP in Publications 23 and 89 and (2) whole-body height and weight percentile data from the National Health and Nutrition Examination Survey (NHANES 1999–2002). The NHANES height and weight data for 19 year old males and females are used to estimate the distributions of individuals’ size, which is unknown, that corresponds to the ICRP organ and tissue distributions. This paper then demonstrates the usage of these anthropometric data in the development of deformable anatomical phantoms. A pair of phantoms—modeled entirely in mesh surfaces—of the adult male and female, RPI-adult male (AM) and RPI-adult female (AF) are used as the base for size-adjustable phantoms. To create percentile-specific phantoms from these two base phantoms, organ surface boundaries are carefully altered according to the tabulated anthropometric data. Software algorithms are developed to automatically match the organ volumes and masses with desired values. Finally, these mesh-based, percentile-specific phantoms are converted into voxel-based phantoms for Monte Carlo radiation transport simulations. This paper also compares absorbed organ doses for the RPI-AM-5th-height and -weight percentile phantom (165 cm in height and 56 kg in weight) and the RPI-AM-95th-height and -weight percentile phantom (188 cm in height and 110 kg in weight)with those for theRPI-AM-50th-height and -weight percentile phantom (176 cm in height and 73 kg in weight) from exposures to 0.5 MeV external photon beams. The results suggest a general finding that the phantoms representing a slimmer and shorter individual male received higher absorbed organ doses because of lesser degree of photon attenuation due to smaller amount of body fat. In particular, doses to the prostate and adrenal in the RPI-AM-5th-height and -weight percentile phantom is about 10% greater than those in the RPI-AM-50th-height and -weight percentile phantom approximating the ICRP Reference Man. On the other hand, the doses to the prostate and adrenal in the RPI-AM-95th-height and -weight percentile phantom are approximately 20% greater than those in the RPI-AM-50th-height and -weight percentile phantom. Although this study only considered the photon radiation of limited energies and irradiation geometries, the potential to improve the organ dose accuracy using the deformable phantom technology is clearly demonstrated. PMID:20551505

[The mechanism of the transport of organophosphorus compounds across the histo-hematic barriers].

PubMed

Miroshkina, V N; Kosmachev, A B; Salova, L S

1999-01-01

It was demonstrated in experiments on mice [correction of rats] that the transport of organophosphorus compounds (OPC) through membranes of the histohematic barriers (HHB) of the organism occurs by means of diffusion. The rate of this process depends on the interaction of OPC with the specific sites of binding with the tissues, among which the enzyme carboxylesterase plays an important part. It is suggested that both the rate and direction of OPC diffusion are determined by the relationship between the values of affinity of the ligands for the sites of their specific binding found on both sides of the HHB.

Pulmonary arterial hypertension associated with chronic active Epstein-Barr virus infection.

PubMed

Hashimoto, Takahiro; Sakata, Yasushi; Fukushima, Kentaro; Maeda, Tetsuo; Arita, Yoh; Shioyama, Wataru; Nakaoka, Yoshikazu; Hori, Yumiko; Morii, Eiichi; Aozasa, Katsuyuki; Kanakura, Yuzuru; Yamauchi-Takihara, Keiko; Komuro, Issei

2011-01-01

A 45-year-old man with chronic active Epstein-Barr virus (EBV) infection (CAEBV) with natural killer cell type developed pulmonary arterial hypertension (PAH). After chemotherapy, he showed marked depression of the EBV DNA genome in the peripheral blood, but PAH sustained. He died of heart failure due to PAH, and the histo-pathological examination revealed pulmonary vascular abnormalities without lung disease on autopsy. Although the EBV DNA genome and the infiltrating lymphocytes were not detected in the lung, his clinical course suggested that his PAH might be caused by CAEBV. This is the first reported case of PAH associated CAEBV in an adult.

The gender perspective in cancer research and therapy: novel insights and on-going hypotheses.

PubMed

Gabriele, Lucia; Buoncervello, Maria; Ascione, Barbara; Bellenghi, Maria; Matarrese, Paola; Carè, Alessandra

2016-01-01

Cancer represents a leading cause of death whose incidence is steadily increasing worldwide due to the population aging. The Global Health Observatory of the World Health Organization reported that approximately 13% of all deaths are caused by cancer. In the 2012 the estimated total number of cancer deaths was 1.75 million, 56% in men and 44% in women. Gender is recognized to play a role in cancer incidence, progression and response to therapy. Besides anatomical and hormonal disparities, genetic differences should be considered when assessing the effects of gender on cancer. Accumulating evidence also support the existence of sex-driven differences in immune responses. Until today clinical trials and research in animal models have been gender unbalanced. In consideration of the differences between sexes observed in cancer, sex should represent an important stratification factor to be included in all randomized clinical trials for a better understanding of biological differences between men and women, which may yield improved targeted therapies.

Differences in subependymal vein anatomy may predispose preterm infants to GMH-IVH.

PubMed

Tortora, Domenico; Severino, Mariasavina; Malova, Mariya; Parodi, Alessandro; Morana, Giovanni; Sedlacik, Jan; Govaert, Paul; Volpe, Joseph J; Rossi, Andrea; Ramenghi, Luca Antonio

2018-01-01

The anatomy of the deep venous system plays an important role in the pathogenesis of brain lesions in the preterm brain as shown by different histological studies. The aims of this study were to compare the subependymal vein anatomy of preterm neonates with germinal matrix haemorrhage-intraventricular haemorrhage (GMH-IVH), as evaluated by susceptibility-weighted imaging (SWI) venography, with a group of age-matched controls with normal brain MRI, and to explore the relationship between the anatomical features of subependymal veins and clinical risk factors for GMH-IVH. SWI venographies of 48 neonates with GMH-IVH and 130 neonates with normal brain MRI were retrospectively evaluated. Subependymal vein anatomy was classified into six different patterns: type 1 represented the classic pattern and types 2-6 were considered anatomic variants. A quantitative analysis of the venous curvature index was performed. Variables were analysed by using Mann-Whitney U and χ 2 tests, and a multiple logistic regression analysis was performed to evaluate the association between anatomical features, clinical factors and GMH-IVH. A significant difference was noticed among the six anatomical patterns according to the presence of GMH-IVH (χ 2 =14.242, p=0.014). Anatomic variants were observed with higher frequency in neonates with GMH-IVH than in controls (62.2% and 49.6%, respectively). Neonates with GMH-IVH presented a narrower curvature of the terminal portion of subependymal veins (p<0.05). These anatomical features were significantly associated with GMH-IVH (p<0.05). Preterm neonates with GMH-IVH show higher variability of subependymal veins anatomy confirming a potential role as predisposing factor for GMH-IVH. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

‘Vividness’ in english natural history and anatomy, 1650–1700

PubMed Central

Wragge-Morley, Alexander

2012-01-01

This article concerns the use of rhetorical strategies in the natural historical and anatomical works of the seventeenth-century Royal Society. Choosing representative works, it argues that naturalists such as Nehemiah Grew, John Ray and the neuroanatomist Thomas Willis used the rhetorical device known as ‘comparison’ to make their descriptions of natural things vivid. By turning to contemporary works of neurology such as Willis's Cerebri Anatome and contemporary rhetorical works inspired by other such descriptions of the brain and nerves, it is argued that the effects of these strategies were taken to be wide-ranging. Contemporaries understood the effects of rhetoric in terms inflected by anatomical and medical discourse—the brain was physically altered by powerful sense impressions such as those of rhetoric. I suggest that the rhetoric of natural history could have been understood in the same way and that natural history and anatomy might therefore have been understood to cultivate the mind, improving its capacity for moral judgements as well as giving it knowledge of nature.

Vertebrobasilar junction giant aneurysm: Lessons learned from a neurosurgical audit and anatomical investigation.

PubMed

Graziano, Francesca; Ganau, Mario; Russo, Vittorio Maria; Iacopino, Domenico G; Ulm, Arthur John

2015-01-01

The treatment of vascular lesions of the vertebrobasilar junction (VBJ) remains a challenging task in the neurosurgical practice and the gold standard therapy is still under debate. In this article, the authors report a detailed postmortem study of a VBJ giant aneurysm (GA) previously endovascularly treated. Although the decision-making process for the vast majority of neurosurgical treatment can nowadays be accurately carried out during the preoperative planning (i.e., with the aid of neuroimaging fusion protocols, neuronavigation platforms, etc.) meant to maximize the anatomical understanding of the lesions and minimize possible intraprocedural challenges, this postmortem study represents the ultimate essence of neurosurgical audit as the laboratory investigations allowed to reevaluate the clinical history of VBJ GA, and reassess the multiple strategies available for its treatment with a straightforward anatomical perspective. Specifically, the lessons learned through this clinical and laboratory work uphold a great educational value regarding the complex management of those lesions, including the possible role of combined skull base surgical approaches.

Transforming Clinical Imaging Data for Virtual Reality Learning Objects

ERIC Educational Resources Information Center

Trelease, Robert B.; Rosset, Antoine

2008-01-01

Advances in anatomical informatics, three-dimensional (3D) modeling, and virtual reality (VR) methods have made computer-based structural visualization a practical tool for education. In this article, the authors describe streamlined methods for producing VR "learning objects," standardized interactive software modules for anatomical sciences…

Anatomical Data for Analyzing Human Motion.

ERIC Educational Resources Information Center

Plagenhoef, Stanley; And Others

1983-01-01

Anatomical data obtained from cadavers and from water displacement studies with living subjects were used to determine the weight, center of gravity, and radius of gyration for 16 body segments. A lead model was used to study movement patterns of the trunk section of the body. (Authors/PP)

Correction for partial volume effect in PET blood flow images

NASA Astrophysics Data System (ADS)

Gage, Howard D.; Fahey, Fredrick H.; Santago, Peter, II; Harkness, Beth A.; Keyes, J. W.

1996-04-01

Current positron emission tomography techniques for the measurement of cerebral blood flow assume that voxels represent pure material regions. In this work, a method is presented which utilizes anatomical information from a high resolution modality such as MRI in conjunction with a multicompartment extension of the Kety model to obtain intravoxel, tissue specific blood flow values. In order to evaluate the proposed method, noisy time activity curves (TACs) were simulated representing different combinations of gray matter, white matter and CSF, and ratios of gray to white matter blood flow. In all experiments it was assumed that registered MR data supplied the number of materials and the fraction of each present. For each TAC, three experiments were run. In the first it was assumed that the fraction of each material determined by MRI was correct, and, in the second two, that the value was either too high or too low. Using the tree annealing method, material flows were determined which gave the best fit of the model to the simulated TAC data. The results indicate that the accuracy of the method is approximately linearly related to the error in material fraction estimated for a voxel.

Bayesian reconstruction and use of anatomical a priori information for emission tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bowsher, J.E.; Johnson, V.E.; Turkington, T.G.

1996-10-01

A Bayesian method is presented for simultaneously segmenting and reconstructing emission computed tomography (ECT) images and for incorporating high-resolution, anatomical information into those reconstructions. The anatomical information is often available from other imaging modalities such as computed tomography (CT) or magnetic resonance imaging (MRI). The Bayesian procedure models the ECT radiopharmaceutical distribution as consisting of regions, such that radiopharmaceutical activity is similar throughout each region. It estimates the number of regions, the mean activity of each region, and the region classification and mean activity of each voxel. Anatomical information is incorporated by assigning higher prior probabilities to ECT segmentations inmore » which each ECT region stays within a single anatomical region. This approach is effective because anatomical tissue type often strongly influences radiopharmaceutical uptake. The Bayesian procedure is evaluated using physically acquired single-photon emission computed tomography (SPECT) projection data and MRI for the three-dimensional (3-D) Hoffman brain phantom. A clinically realistic count level is used. A cold lesion within the brain phantom is created during the SPECT scan but not during the MRI to demonstrate that the estimation procedure can detect ECT structure that is not present anatomically.« less

Amyloidosis involving the respiratory system: 5-year's experience of a multi-disciplinary group's activity.

PubMed

Scala, Raffaele; Maccari, Uberto; Madioni, Chiara; Venezia, Duccio; La Magra, Lidia Calogera

2015-01-01

Amyloidosis may involve the respiratory system with different clinical-radiological-functional patterns which are not always easy to be recognized. A good level of knowledge of the disease, an active integration of the pulmonologist within a multidisciplinary setting and a high level of clinical suspicion are necessary for an early diagnosis of respiratory amyloidosis. The aim of this retrospective study was to evaluate the number and the patterns of amyloidosis involving the respiratory system. We searched the cases of amyloidosis among patients attending the multidisciplinary rare and diffuse lung disease outpatients' clinic of Pulmonology Unit of the Hospital of Arezzo from 2007 to 2012. Among the 298 patients evaluated during the study period, we identified three cases of amyloidosis with involvement of the respiratory system, associated or not with other extra-thoracic localizations, whose diagnosis was histo-pathologically confirmed after the pulmonologist, the radiologist, and the pathologist evaluation. Our experience of a multidisciplinary team confirms that intra-thoracic amyloidosis is an uncommon disorder, representing 1.0% of the cases of rare and diffuse lung diseases referred to our center. The diagnosis of the disease is not always easy and quick as the amyloidosis may involve different parts of the respiratory system (airways, pleura, parenchyma). It is therefore recommended to remind this orphan disease in the differential diagnosis of the wide clinical scenarios the pulmonologist may intercept in clinical practice.

Amyloidosis involving the respiratory system: 5-year's experience of a multi-disciplinary group's activity

PubMed Central

Scala, Raffaele; Maccari, Uberto; Madioni, Chiara; Venezia, Duccio; La Magra, Lidia Calogera

2015-01-01

Amyloidosis may involve the respiratory system with different clinical-radiological-functional patterns which are not always easy to be recognized. A good level of knowledge of the disease, an active integration of the pulmonologist within a multidisciplinary setting and a high level of clinical suspicion are necessary for an early diagnosis of respiratory amyloidosis. The aim of this retrospective study was to evaluate the number and the patterns of amyloidosis involving the respiratory system. We searched the cases of amyloidosis among patients attending the multidisciplinary rare and diffuse lung disease outpatients' clinic of Pulmonology Unit of the Hospital of Arezzo from 2007 to 2012. Among the 298 patients evaluated during the study period, we identified three cases of amyloidosis with involvement of the respiratory system, associated or not with other extra-thoracic localizations, whose diagnosis was histo-pathologically confirmed after the pulmonologist, the radiologist, and the pathologist evaluation. Our experience of a multidisciplinary team confirms that intra-thoracic amyloidosis is an uncommon disorder, representing 1.0% of the cases of rare and diffuse lung diseases referred to our center. The diagnosis of the disease is not always easy and quick as the amyloidosis may involve different parts of the respiratory system (airways, pleura, parenchyma). It is therefore recommended to remind this orphan disease in the differential diagnosis of the wide clinical scenarios the pulmonologist may intercept in clinical practice. PMID:26229565

Clinical anatomy of the subserous layer: An amalgamation of gross and clinical anatomy.

PubMed

Yabuki, Yoshihiko

2016-05-01

The 1998 edition of Terminologia Anatomica introduced some currently used clinical anatomical terms for the pelvic connective tissue or subserous layer. These innovations persuaded the present author to consider a format in which the clinical anatomical terms could be reconciled with those of gross anatomy and incorporated into a single anatomical glossary without contradiction or ambiguity. Specific studies on the subserous layer were undertaken on 79 Japanese women who had undergone surgery for uterine cervical cancer, and on 26 female cadavers that were dissected, 17 being formalin-fixed and 9 fresh. The results were as follows: (a) the subserous layer could be segmentalized by surgical dissection in the perpendicular, horizontal and sagittal planes; (b) the segmentalized subserous layer corresponded to 12 cubes, or ligaments, of minimal dimension that enabled the pelvic organs to be extirpated; (c) each ligament had a three-dimensional (3D) structure comprising craniocaudal, mediolateral, and dorsoventral directions vis-á-vis the pelvic axis; (d) these 3D-structured ligaments were encoded morphologically in order of decreasing length; and (e) using these codes, all the surgical procedures for 19th century to present-day radical hysterectomy could be expressed symbolically. The establishment of clinical anatomical terms, represented symbolically through coding as demonstrated in this article, could provide common ground for amalgamating clinical anatomy with gross anatomy. Consequently, terms in clinical anatomy and gross anatomy could be reconciled and compiled into a single anatomical glossary. © 2015 Wiley Periodicals, Inc.

Design and Validation of 3D Printed Complex Bone Models with Internal Anatomic Fidelity for Surgical Training and Rehearsal.

PubMed

Unger, Bertram J; Kraut, Jay; Rhodes, Charlotte; Hochman, Jordan

2014-01-01

Physical models of complex bony structures can be used for surgical skills training. Current models focus on surface rendering but suffer from a lack of internal accuracy due to limitations in the manufacturing process. We describe a technique for generating internally accurate rapid-prototyped anatomical models with solid and hollow structures from clinical and microCT data using a 3D printer. In a face validation experiment, otolaryngology residents drilled a cadaveric bone and its corresponding printed model. The printed bone models were deemed highly realistic representations across all measured parameters and the educational value of the models was strongly appreciated.

Particle image velocimetry measurements in an anatomical vascular model fabricated using inkjet 3D printing

NASA Astrophysics Data System (ADS)

Aycock, Kenneth I.; Hariharan, Prasanna; Craven, Brent A.

2017-11-01

For decades, the study of biomedical fluid dynamics using optical flow visualization and measurement techniques has been limited by the inability to fabricate transparent physical models that realistically replicate the complex morphology of biological lumens. In this study, we present an approach for producing optically transparent anatomical models that are suitable for particle image velocimetry (PIV) using a common 3D inkjet printing process (PolyJet) and stock resin (VeroClear). By matching the index of refraction of the VeroClear material using a room-temperature mixture of water, sodium iodide, and glycerol, and by printing the part in an orientation such that the flat, optical surfaces are at an approximately 45° angle to the build plane, we overcome the challenges associated with using this 3D printing technique for PIV. Here, we summarize our methodology and demonstrate the process and the resultant PIV measurements of flow in an optically transparent anatomical model of the human inferior vena cava.

CT-based manual segmentation and evaluation of paranasal sinuses.

PubMed

Pirner, S; Tingelhoff, K; Wagner, I; Westphal, R; Rilk, M; Wahl, F M; Bootz, F; Eichhorn, Klaus W G

2009-04-01

Manual segmentation of computed tomography (CT) datasets was performed for robot-assisted endoscope movement during functional endoscopic sinus surgery (FESS). Segmented 3D models are needed for the robots' workspace definition. A total of 50 preselected CT datasets were each segmented in 150-200 coronal slices with 24 landmarks being set. Three different colors for segmentation represent diverse risk areas. Extension and volumetric measurements were performed. Three-dimensional reconstruction was generated after segmentation. Manual segmentation took 8-10 h for each CT dataset. The mean volumes were: right maxillary sinus 17.4 cm(3), left side 17.9 cm(3), right frontal sinus 4.2 cm(3), left side 4.0 cm(3), total frontal sinuses 7.9 cm(3), sphenoid sinus right side 5.3 cm(3), left side 5.5 cm(3), total sphenoid sinus volume 11.2 cm(3). Our manually segmented 3D-models present the patient's individual anatomy with a special focus on structures in danger according to the diverse colored risk areas. For safe robot assistance, the high-accuracy models represent an average of the population for anatomical variations, extension and volumetric measurements. They can be used as a database for automatic model-based segmentation. None of the segmentation methods so far described provide risk segmentation. The robot's maximum distance to the segmented border can be adjusted according to the differently colored areas.

Automatic construction of subject-specific human airway geometry including trifurcations based on a CT-segmented airway skeleton and surface

PubMed Central

Miyawaki, Shinjiro; Tawhai, Merryn H.; Hoffman, Eric A.; Wenzel, Sally E.; Lin, Ching-Long

2016-01-01

We propose a method to construct three-dimensional airway geometric models based on airway skeletons, or centerlines (CLs). Given a CT-segmented airway skeleton and surface, the proposed CL-based method automatically constructs subject-specific models that contain anatomical information regarding branches, include bifurcations and trifurcations, and extend from the trachea to terminal bronchioles. The resulting model can be anatomically realistic with the assistance of an image-based surface; alternatively a model with an idealized skeleton and/or branch diameters is also possible. This method systematically identifies and classifies trifurcations to successfully construct the models, which also provides the number and type of trifurcations for the analysis of the airways from an anatomical point of view. We applied this method to 16 normal and 16 severe asthmatic subjects using their computed tomography images. The average distance between the surface of the model and the image-based surface was 11% of the average voxel size of the image. The four most frequent locations of trifurcations were the left upper division bronchus, left lower lobar bronchus, right upper lobar bronchus, and right intermediate bronchus. The proposed method automatically constructed accurate subject-specific three-dimensional airway geometric models that contain anatomical information regarding branches using airway skeleton, diameters, and image-based surface geometry. The proposed method can construct (i) geometry automatically for population-based studies, (ii) trifurcations to retain the original airway topology, (iii) geometry that can be used for automatic generation of computational fluid dynamics meshes, and (iv) geometry based only on a skeleton and diameters for idealized branches. PMID:27704229

Use of a real-size 3D-printed model as a preoperative and intraoperative tool for minimally invasive plating of comminuted midshaft clavicle fractures.

PubMed

Kim, Hyong Nyun; Liu, Xiao Ning; Noh, Kyu Cheol

2015-06-10

Open reduction and plate fixation is the standard operative treatment for displaced midshaft clavicle fracture. However, sometimes it is difficult to achieve anatomic reduction by open reduction technique in cases with comminution. We describe a novel technique using a real-size three dimensionally (3D)-printed clavicle model as a preoperative and intraoperative tool for minimally invasive plating of displaced comminuted midshaft clavicle fractures. A computed tomography (CT) scan is taken of both clavicles in patients with a unilateral displaced comminuted midshaft clavicle fracture. Both clavicles are 3D printed into a real-size clavicle model. Using the mirror imaging technique, the uninjured side clavicle is 3D printed into the opposite side model to produce a suitable replica of the fractured side clavicle pre-injury. The 3D-printed fractured clavicle model allows the surgeon to observe and manipulate accurate anatomical replicas of the fractured bone to assist in fracture reduction prior to surgery. The 3D-printed uninjured clavicle model can be utilized as a template to select the anatomically precontoured locking plate which best fits the model. The plate can be inserted through a small incision and fixed with locking screws without exposing the fracture site. Seven comminuted clavicle fractures treated with this technique achieved good bone union. This technique can be used for a unilateral displaced comminuted midshaft clavicle fracture when it is difficult to achieve anatomic reduction by open reduction technique. Level of evidence V.

Anatomically-Aided PET Reconstruction Using the Kernel Method

PubMed Central

Hutchcroft, Will; Wang, Guobao; Chen, Kevin T.; Catana, Ciprian; Qi, Jinyi

2016-01-01

This paper extends the kernel method that was proposed previously for dynamic PET reconstruction, to incorporate anatomical side information into the PET reconstruction model. In contrast to existing methods that incorporate anatomical information using a penalized likelihood framework, the proposed method incorporates this information in the simpler maximum likelihood (ML) formulation and is amenable to ordered subsets. The new method also does not require any segmentation of the anatomical image to obtain edge information. We compare the kernel method with the Bowsher method for anatomically-aided PET image reconstruction through a simulated data set. Computer simulations demonstrate that the kernel method offers advantages over the Bowsher method in region of interest (ROI) quantification. Additionally the kernel method is applied to a 3D patient data set. The kernel method results in reduced noise at a matched contrast level compared with the conventional ML expectation maximization (EM) algorithm. PMID:27541810

Anatomically-aided PET reconstruction using the kernel method.

PubMed

Hutchcroft, Will; Wang, Guobao; Chen, Kevin T; Catana, Ciprian; Qi, Jinyi

2016-09-21

This paper extends the kernel method that was proposed previously for dynamic PET reconstruction, to incorporate anatomical side information into the PET reconstruction model. In contrast to existing methods that incorporate anatomical information using a penalized likelihood framework, the proposed method incorporates this information in the simpler maximum likelihood (ML) formulation and is amenable to ordered subsets. The new method also does not require any segmentation of the anatomical image to obtain edge information. We compare the kernel method with the Bowsher method for anatomically-aided PET image reconstruction through a simulated data set. Computer simulations demonstrate that the kernel method offers advantages over the Bowsher method in region of interest quantification. Additionally the kernel method is applied to a 3D patient data set. The kernel method results in reduced noise at a matched contrast level compared with the conventional ML expectation maximization algorithm.

Anatomically-aided PET reconstruction using the kernel method

NASA Astrophysics Data System (ADS)

Hutchcroft, Will; Wang, Guobao; Chen, Kevin T.; Catana, Ciprian; Qi, Jinyi

2016-09-01

This paper extends the kernel method that was proposed previously for dynamic PET reconstruction, to incorporate anatomical side information into the PET reconstruction model. In contrast to existing methods that incorporate anatomical information using a penalized likelihood framework, the proposed method incorporates this information in the simpler maximum likelihood (ML) formulation and is amenable to ordered subsets. The new method also does not require any segmentation of the anatomical image to obtain edge information. We compare the kernel method with the Bowsher method for anatomically-aided PET image reconstruction through a simulated data set. Computer simulations demonstrate that the kernel method offers advantages over the Bowsher method in region of interest quantification. Additionally the kernel method is applied to a 3D patient data set. The kernel method results in reduced noise at a matched contrast level compared with the conventional ML expectation maximization algorithm.

Interactive anatomical teaching: Integrating radiological anatomy within topographic anatomy.

PubMed

Abed Rabbo, F; Garrigues, F; Lefèvre, C; Seizeur, R

2016-03-01

Hours attributed to teaching anatomy have been reduced in medical curricula through out the world. In consequence, changes in anatomical curriculum as well as in teaching methods are becoming necessary. New methods of teaching are being evaluated. We present in the following paper an example of interactive anatomical teaching associating topographic anatomy with ultrasonographic radiological anatomy. The aim was to explicitly show anatomical structures of the knee and the ankle through dissection and ultrasonography. One cadaver was used as an ultrasonographic model and the other was dissected. Anatomy of the knee and ankle articulations was studied through dissection and ultrasonography. The students were able to simultaneously assimilate both anatomical aspects of radiological and topographic anatomy. They found the teaching very helpful and practical. This body of work provides example of a teaching method combining two important aspects of anatomy to help the students understand both aspects simultaneously. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Do Three-dimensional Visualization and Three-dimensional Printing Improve Hepatic Segment Anatomy Teaching? A Randomized Controlled Study.

PubMed

Kong, Xiangxue; Nie, Lanying; Zhang, Huijian; Wang, Zhanglin; Ye, Qiang; Tang, Lei; Li, Jianyi; Huang, Wenhua

2016-01-01

Hepatic segment anatomy is difficult for medical students to learn. Three-dimensional visualization (3DV) is a useful tool in anatomy teaching, but current models do not capture haptic qualities. However, three-dimensional printing (3DP) can produce highly accurate complex physical models. Therefore, in this study we aimed to develop a novel 3DP hepatic segment model and compare the teaching effectiveness of a 3DV model, a 3DP model, and a traditional anatomical atlas. A healthy candidate (female, 50-years old) was recruited and scanned with computed tomography. After three-dimensional (3D) reconstruction, the computed 3D images of the hepatic structures were obtained. The parenchyma model was divided into 8 hepatic segments to produce the 3DV hepatic segment model. The computed 3DP model was designed by removing the surrounding parenchyma and leaving the segmental partitions. Then, 6 experts evaluated the 3DV and 3DP models using a 5-point Likert scale. A randomized controlled trial was conducted to evaluate the educational effectiveness of these models compared with that of the traditional anatomical atlas. The 3DP model successfully displayed the hepatic segment structures with partitions. All experts agreed or strongly agreed that the 3D models provided good realism for anatomical instruction, with no significant differences between the 3DV and 3DP models in each index (p > 0.05). Additionally, the teaching effects show that the 3DV and 3DP models were significantly better than traditional anatomical atlas in the first and second examinations (p < 0.05). Between the first and second examinations, only the traditional method group had significant declines (p < 0.05). A novel 3DP hepatic segment model was successfully developed. Both the 3DV and 3DP models could improve anatomy teaching significantly. Copyright © 2015 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Eye model for the ground squirrel

NASA Astrophysics Data System (ADS)

Sussman, Dafna; Chou, B. Ralph; Lakshminarayanan, Vasudevan

2011-11-01

This paper presents an anatomically-correct eye model for the ground squirrel, a diurnal, highly-developed mammal with high visual acuity. This model can assist in understanding the relationship between ocular structural development and its corresponding function. The eye model is constructed based on anatomical measurements of thicknesses and indices of refraction of the various ocular media. The model then derives the gradient index distribution of the crystalline lens using a ray tracing method with a Monte Carlo optimization. Results indicate a diffraction-limited ocular behaviour, implying the visual acuity of the ground squirrel is more likely to be limited by photoreceptor density and diffraction effects, than by ocular geometry.

Creation of Anatomically Accurate Computer-Aided Design (CAD) Solid Models from Medical Images

NASA Technical Reports Server (NTRS)

Stewart, John E.; Graham, R. Scott; Samareh, Jamshid A.; Oberlander, Eric J.; Broaddus, William C.

1999-01-01

Most surgical instrumentation and implants used in the world today are designed with sophisticated Computer-Aided Design (CAD)/Computer-Aided Manufacturing (CAM) software. This software automates the mechanical development of a product from its conceptual design through manufacturing. CAD software also provides a means of manipulating solid models prior to Finite Element Modeling (FEM). Few surgical products are designed in conjunction with accurate CAD models of human anatomy because of the difficulty with which these models are created. We have developed a novel technique that creates anatomically accurate, patient specific CAD solids from medical images in a matter of minutes.

Response of local vascular volumes to lower body negative pressure stress

NASA Technical Reports Server (NTRS)

Wolthuis, R. A.; Leblanc, A.; Carpentier, W. A.; Bergman, S. A., Jr.

1975-01-01

The present study involved an intravenous injection of radioactive iodinated serum albumin, equilibration of this isotope within the vascular space, and the continuous measurement of isotope activity over selected anatomical areas before, during and following multiple human LBNP tests. Both rate and magnitude of vascular pooling were distinctly different within each of five selected lower body anatomical areas. In the upper body, all areas except the abdomen showed depletions from their resting vascular volumes during LBNP. The presence of uniquely different pooling patterns in the lower body, the apparent stability of abdominal vascular volumes, and a possible decrease in cerebral blood volume during LBNP represent the major findings of this study.

Recent development on computer aided tissue engineering--a review.

PubMed

Sun, Wei; Lal, Pallavi

2002-02-01

The utilization of computer-aided technologies in tissue engineering has evolved in the development of a new field of computer-aided tissue engineering (CATE). This article reviews recent development and application of enabling computer technology, imaging technology, computer-aided design and computer-aided manufacturing (CAD and CAM), and rapid prototyping (RP) technology in tissue engineering, particularly, in computer-aided tissue anatomical modeling, three-dimensional (3-D) anatomy visualization and 3-D reconstruction, CAD-based anatomical modeling, computer-aided tissue classification, computer-aided tissue implantation and prototype modeling assisted surgical planning and reconstruction.

An analysis of multi-type relational interactions in FMA using graph motifs with disjointness constraints.

PubMed

Zhang, Guo-Qiang; Luo, Lingyun; Ogbuji, Chime; Joslyn, Cliff; Mejino, Jose; Sahoo, Satya S

2012-01-01

The interaction of multiple types of relationships among anatomical classes in the Foundational Model of Anatomy (FMA) can provide inferred information valuable for quality assurance. This paper introduces a method called Motif Checking (MOCH) to study the effects of such multi-relation type interactions for detecting logical inconsistencies as well as other anomalies represented by the motifs. MOCH represents patterns of multi-type interaction as small labeled (with multiple types of edges) sub-graph motifs, whose nodes represent class variables, and labeled edges represent relational types. By representing FMA as an RDF graph and motifs as SPARQL queries, fragments of FMA are automatically obtained as auditing candidates. Leveraging the scalability and reconfigurability of Semantic Web Technology, we performed exhaustive analyses of a variety of labeled sub-graph motifs. The quality assurance feature of MOCH comes from the distinct use of a subset of the edges of the graph motifs as constraints for disjointness, whereby bringing in rule-based flavor to the approach as well. With possible disjointness implied by antonyms, we performed manual inspection of the resulting FMA fragments and tracked down sources of abnormal inferred conclusions (logical inconsistencies), which are amendable for programmatic revision of the FMA. Our results demonstrate that MOCH provides a unique source of valuable information for quality assurance. Since our approach is general, it is applicable to any ontological system with an OWL representation.

An Analysis of Multi-type Relational Interactions in FMA Using Graph Motifs with Disjointness Constraints

PubMed Central

Zhang, Guo-Qiang; Luo, Lingyun; Ogbuji, Chime; Joslyn, Cliff; Mejino, Jose; Sahoo, Satya S

2012-01-01

The interaction of multiple types of relationships among anatomical classes in the Foundational Model of Anatomy (FMA) can provide inferred information valuable for quality assurance. This paper introduces a method called Motif Checking (MOCH) to study the effects of such multi-relation type interactions for detecting logical inconsistencies as well as other anomalies represented by the motifs. MOCH represents patterns of multi-type interaction as small labeled (with multiple types of edges) sub-graph motifs, whose nodes represent class variables, and labeled edges represent relational types. By representing FMA as an RDF graph and motifs as SPARQL queries, fragments of FMA are automatically obtained as auditing candidates. Leveraging the scalability and reconfigurability of Semantic Web Technology, we performed exhaustive analyses of a variety of labeled sub-graph motifs. The quality assurance feature of MOCH comes from the distinct use of a subset of the edges of the graph motifs as constraints for disjointness, whereby bringing in rule-based flavor to the approach as well. With possible disjointness implied by antonyms, we performed manual inspection of the resulting FMA fragments and tracked down sources of abnormal inferred conclusions (logical inconsistencies), which are amendable for programmatic revision of the FMA. Our results demonstrate that MOCH provides a unique source of valuable information for quality assurance. Since our approach is general, it is applicable to any ontological system with an OWL representation. PMID:23304382

Standards to support information systems integration in anatomic pathology.

PubMed

Daniel, Christel; García Rojo, Marcial; Bourquard, Karima; Henin, Dominique; Schrader, Thomas; Della Mea, Vincenzo; Gilbertson, John; Beckwith, Bruce A

2009-11-01

Integrating anatomic pathology information- text and images-into electronic health care records is a key challenge for enhancing clinical information exchange between anatomic pathologists and clinicians. The aim of the Integrating the Healthcare Enterprise (IHE) international initiative is precisely to ensure interoperability of clinical information systems by using existing widespread industry standards such as Digital Imaging and Communication in Medicine (DICOM) and Health Level Seven (HL7). To define standard-based informatics transactions to integrate anatomic pathology information to the Healthcare Enterprise. We used the methodology of the IHE initiative. Working groups from IHE, HL7, and DICOM, with special interest in anatomic pathology, defined consensual technical solutions to provide end-users with improved access to consistent information across multiple information systems. The IHE anatomic pathology technical framework describes a first integration profile, "Anatomic Pathology Workflow," dedicated to the diagnostic process including basic image acquisition and reporting solutions. This integration profile relies on 10 transactions based on HL7 or DICOM standards. A common specimen model was defined to consistently identify and describe specimens in both HL7 and DICOM transactions. The IHE anatomic pathology working group has defined standard-based informatics transactions to support the basic diagnostic workflow in anatomic pathology laboratories. In further stages, the technical framework will be completed to manage whole-slide images and semantically rich structured reports in the diagnostic workflow and to integrate systems used for patient care and those used for research activities (such as tissue bank databases or tissue microarrayers).

Constructivist Learning of Anatomy: Gaining Knowledge by Creating Anatomical Casts

ERIC Educational Resources Information Center

Hermiz, David J.; O'Sullivan, Daniel J.; Lujan, Heidi L.; DiCarlo, Stephen E.

2011-01-01

Educators are encouraged to provide inquiry-based, collaborative, and problem solving activities that enhance learning and promote curiosity, skepticism, objectivity, and the use of scientific reasoning. Making anatomical casts or models by injecting solidifying substances into organs is an example of a constructivist activity for achieving these…

Automated anatomical description of pleural thickening towards improvement of its computer-assisted diagnosis

NASA Astrophysics Data System (ADS)

Chaisaowong, Kraisorn; Jiang, Mingze; Faltin, Peter; Merhof, Dorit; Eisenhawer, Christian; Gube, Monika; Kraus, Thomas

2016-03-01

Pleural thickenings are caused by asbestos exposure and may evolve into malignant pleural mesothelioma. An early diagnosis plays a key role towards an early treatment and an increased survival rate. Today, pleural thickenings are detected by visual inspection of CT data, which is time-consuming and underlies the physician's subjective judgment. A computer-assisted diagnosis system to automatically assess pleural thickenings has been developed, which includes not only a quantitative assessment with respect to size and location, but also enhances this information with an anatomical description, i.e. lung side (left, right), part of pleura (pars costalis, mediastinalis, diaphragmatica, spinalis), as well as vertical (upper, middle, lower) and horizontal (ventral, dorsal) position. For this purpose, a 3D anatomical model of the lung surface has been manually constructed as a 3D atlas. Three registration sub-steps including rigid, affine, and nonrigid registration align the input patient lung to the 3D anatomical atlas model of the lung surface. Finally, each detected pleural thickening is assigned a set of labels describing its anatomical properties. Through this added information, an enhancement to the existing computer-assisted diagnosis system is presented in order to assure a higher precision and reproducible assessment of pleural thickenings, aiming at the diagnosis of the pleural mesothelioma in its early stage.

Scaled Anatomical Model Creation of Biomedical Tomographic Imaging Data and Associated Labels for Subsequent Sub-surface Laser Engraving (SSLE) of Glass Crystals

PubMed Central

Dethlefs, Christopher R.; Piotrowicz, Justin; Van Avermaete, Tony; Maki, Jeff; Gerstler, Steve; Leevy, W. M.

2017-01-01

Biomedical imaging modalities like computed tomography (CT) and magnetic resonance (MR) provide excellent platforms for collecting three-dimensional data sets of patient or specimen anatomy in clinical or preclinical settings. However, the use of a virtual, on-screen display limits the ability of these tomographic images to fully convey the anatomical information embedded within. One solution is to interface a biomedical imaging data set with 3D printing technology to generate a physical replica. Here we detail a complementary method to visualize tomographic imaging data with a hand-held model: Sub Surface Laser Engraving (SSLE) of crystal glass. SSLE offers several unique benefits including: the facile ability to include anatomical labels, as well as a scale bar; streamlined multipart assembly of complex structures in one medium; high resolution in the X, Y, and Z planes; and semi-transparent shells for visualization of internal anatomical substructures. Here we demonstrate the process of SSLE with CT data sets derived from pre-clinical and clinical sources. This protocol will serve as a powerful and inexpensive new tool with which to visualize complex anatomical structures for scientists and students in a number of educational and research settings. PMID:28518066

Development of new anatomy reconstruction software to localize cardiac isochrones to the cardiac surface from the 12 lead ECG.

PubMed

van Dam, Peter M; Gordon, Jeffrey P; Laks, Michael M; Boyle, Noel G

2015-01-01

Non-invasive electrocardiographic imaging (ECGI) of the cardiac muscle can help the pre-procedure planning of the ablation of ventricular arrhythmias by reducing the time to localize the origin. Our non-invasive ECGI system, the cardiac isochrone positioning system (CIPS), requires non-intersecting meshes of the heart, lungs and torso. However, software to reconstruct the meshes of the heart, lungs and torso with the capability to check and prevent these intersections is currently lacking. Consequently the reconstruction of a patient specific model with realistic atrial and ventricular wall thickness and incorporating blood cavities, lungs and torso usually requires additional several days of manual work. Therefore new software was developed that checks and prevents any intersections, and thus enables the use of accurate reconstructed anatomical models within CIPS. In this preliminary study we investigated the accuracy of the created patient specific anatomical models from MRI or CT. During the manual segmentation of the MRI data the boundaries of the relevant tissues are determined. The resulting contour lines are used to automatically morph reference meshes of the heart, lungs or torso to match the boundaries of the morphed tissue. Five patients were included in the study; models of the heart, lungs and torso were reconstructed from standard cardiac MRI images. The accuracy was determined by computing the distance between the segmentation contours and the morphed meshes. The average accuracy of the reconstructed cardiac geometry was within 2mm with respect to the manual segmentation contours on the MRI images. Derived wall volumes and left ventricular wall thickness were within the range reported in literature. For each reconstructed heart model the anatomical heart axis was computed using the automatically determined anatomical landmarks of the left apex and the mitral valve. The accuracy of the reconstructed heart models was well within the accuracy of the used medical image data (pixel size <1.5mm). For the lungs and torso the number of triangles in the mesh was reduced, thus decreasing the accuracy of the reconstructed mesh. A novel software tool has been introduced, which is able to reconstruct accurate cardiac anatomical models from MRI or CT within only a few hours. This new anatomical reconstruction tool might reduce the modeling errors within the cardiac isochrone positioning system and thus enable the clinical application of CIPS to localize the PVC/VT focus to the ventricular myocardium from only the standard 12 lead ECG. Copyright © 2015 Elsevier Inc. All rights reserved.

An Example-Based Brain MRI Simulation Framework.

PubMed

He, Qing; Roy, Snehashis; Jog, Amod; Pham, Dzung L

2015-02-21

The simulation of magnetic resonance (MR) images plays an important role in the validation of image analysis algorithms such as image segmentation, due to lack of sufficient ground truth in real MR images. Previous work on MRI simulation has focused on explicitly modeling the MR image formation process. However, because of the overwhelming complexity of MR acquisition these simulations must involve simplifications and approximations that can result in visually unrealistic simulated images. In this work, we describe an example-based simulation framework, which uses an "atlas" consisting of an MR image and its anatomical models derived from the hard segmentation. The relationships between the MR image intensities and its anatomical models are learned using a patch-based regression that implicitly models the physics of the MR image formation. Given the anatomical models of a new brain, a new MR image can be simulated using the learned regression. This approach has been extended to also simulate intensity inhomogeneity artifacts based on the statistical model of training data. Results show that the example based MRI simulation method is capable of simulating different image contrasts and is robust to different choices of atlas. The simulated images resemble real MR images more than simulations produced by a physics-based model.

A novel medical image data-based multi-physics simulation platform for computational life sciences.

PubMed

Neufeld, Esra; Szczerba, Dominik; Chavannes, Nicolas; Kuster, Niels

2013-04-06

Simulating and modelling complex biological systems in computational life sciences requires specialized software tools that can perform medical image data-based modelling, jointly visualize the data and computational results, and handle large, complex, realistic and often noisy anatomical models. The required novel solvers must provide the power to model the physics, biology and physiology of living tissue within the full complexity of the human anatomy (e.g. neuronal activity, perfusion and ultrasound propagation). A multi-physics simulation platform satisfying these requirements has been developed for applications including device development and optimization, safety assessment, basic research, and treatment planning. This simulation platform consists of detailed, parametrized anatomical models, a segmentation and meshing tool, a wide range of solvers and optimizers, a framework for the rapid development of specialized and parallelized finite element method solvers, a visualization toolkit-based visualization engine, a Python scripting interface for customized applications, a coupling framework, and more. Core components are cross-platform compatible and use open formats. Several examples of applications are presented: hyperthermia cancer treatment planning, tumour growth modelling, evaluating the magneto-haemodynamic effect as a biomarker and physics-based morphing of anatomical models.

Creating vascular models by postprocessing computed tomography angiography images: a guide for anatomical education.

PubMed

Govsa, Figen; Ozer, Mehmet Asim; Sirinturk, Suzan; Eraslan, Cenk; Alagoz, Ahmet Kemal

2017-08-01

A new application of teaching anatomy includes the use of computed tomography angiography (CTA) images to create clinically relevant three-dimensional (3D) printed models. The purpose of this article is to review recent innovations on the process and the application of 3D printed models as a tool for using under and post-graduate medical education. Images of aortic arch pattern received by CTA were converted into 3D images using the Google SketchUp free software and were saved in stereolithography format. Using a 3D printer (Makerbot), a model mode polylactic acid material was printed. A two-vessel left aortic arch was identified consisting of the brachiocephalic trunk and left subclavian artery. The life-like 3D models were rotated 360° in all axes in hand. The early adopters in education and clinical practices have embraced the medical imaging-guided 3D printed anatomical models for their ability to provide tactile feedback and a superior appreciation of visuospatial relationship between the anatomical structures. Printed vascular models are used to assist in preoperative planning, develop intraoperative guidance tools, and to teach patients surgical trainees in surgical practice.

Effect of anatomical variability in brain on transcranial magnetic stimulation treatment

NASA Astrophysics Data System (ADS)

Syeda, F.; Magsood, H.; Lee, E. G.; El-Gendy, A. A.; Jiles, D. C.; Hadimani, R. L.

2017-05-01

Transcranial Magnetic Stimulation is a non-invasive clinical therapy used to treat depression and migraine, and shows further promise as treatment for Parkinson's disease, Alzheimer's disease, and other neurological disorders. However, it is yet unclear as to how anatomical differences may affect stimulation from this treatment. We use finite element analysis to model and analyze the results of Transcranial Magnetic Stimulation in various head models. A number of heterogeneous head models have been developed using MRI data of real patients, including healthy individuals as well as patients of Parkinson's disease. Simulations of Transcranial Magnetic Stimulation performed on 22 anatomically different models highlight the differences in induced stimulation. A standard Figure of 8 coil is used with frequency 2.5 kHz, placed 5 mm above the head. We compare cortical stimulation, volume of brain tissue stimulated, specificity, and maximum E-field induced in the brain for models ranging from ages 20 to 60. Results show that stimulation varies drastically between patients of the same age and health status depending upon brain-scalp distance, which is not necessarily a linear progression with age.

Predictive Models of Cognitive Outcomes of Developmental Insults

NASA Astrophysics Data System (ADS)

Chan, Yupo; Bouaynaya, Nidhal; Chowdhury, Parimal; Leszczynska, Danuta; Patterson, Tucker A.; Tarasenko, Olga

2010-04-01

Representatives of Arkansas medical, research and educational institutions have gathered over the past four years to discuss the relationship between functional developmental perturbations and their neurological consequences. We wish to track the effect on the nervous system by developmental perturbations over time and across species. Except for perturbations, the sequence of events that occur during neural development was found to be remarkably conserved across mammalian species. The tracking includes consequences on anatomical regions and behavioral changes. The ultimate goal is to develop a predictive model of long-term genotypic and phenotypic outcomes that includes developmental insults. Such a model can subsequently be fostered into an educated intervention for therapeutic purposes. Several datasets were identified to test plausible hypotheses, ranging from evoked potential datasets to sleep-disorder datasets. An initial model may be mathematical and conceptual. However, we expect to see rapid progress as large-scale gene expression studies in the mammalian brain permit genome-wide searches to discover genes that are uniquely expressed in brain circuits and regions. These genes ultimately control behavior. By using a validated model we endeavor to make useful predictions.

Nonintrusive 3D reconstruction of human bone models to simulate their bio-mechanical response

NASA Astrophysics Data System (ADS)

Alexander, Tsouknidas; Antonis, Lontos; Savvas, Savvakis; Nikolaos, Michailidis

2012-06-01

3D finite element models representing functional parts of the human skeletal system, have been repeatedly introduced over the last years, to simulate biomechanical response of anatomical characteristics or investigate surgical treatment. The reconstruction of geometrically accurate FEM models, poses a significant challenge for engineers and physicians, as recent advances in tissue engineering dictate highly customized implants, while facilitating the production of alloplast materials that are employed to restore, replace or supplement the function of human tissue. The premises of every accurate reconstruction method, is to encapture the precise geometrical characteristics of the examined tissue and thus the selection of a sufficient imaging technique is of the up-most importance. This paper reviews existing and potential applications related to the current state-of-the-art of medical imaging and simulation techniques. The procedures are examined by introducing their concepts; strengths and limitations, while the authors also present part of their recent activities in these areas. [Figure not available: see fulltext.

Creep Behavior of Passive Bovine Extraocular Muscle

PubMed Central

Yoo, Lawrence; Kim, Hansang; Shin, Andrew; Gupta, Vijay; Demer, Joseph L.

2011-01-01

This paper characterized bovine extraocular muscles (EOMs) using creep, which represents long-term stretching induced by a constant force. After preliminary optimization of testing conditions, 20 fresh EOM samples were subjected to four different loading rates of 1.67, 3.33, 8.33, and 16.67%/s, after which creep was observed for 1,500 s. A published quasilinear viscoelastic (QLV) relaxation function was transformed to a creep function that was compared with data. Repeatable creep was observed for each loading rate and was similar among all six anatomical EOMs. The mean creep coefficient after 1,500 seconds for a wide range of initial loading rates was at 1.37 ± 0.03 (standard deviation, SD). The creep function derived from the relaxation-based QLV model agreed with observed creep to within 2.7% following 16.67%/s ramp loading. Measured creep agrees closely with a derived QLV model of EOM relaxation, validating a previous QLV model for characterization of EOM biomechanics. PMID:22131809

Accuracy and reliability of stitched cone-beam computed tomography images

PubMed Central

Egbert, Nicholas; Cagna, David R.; Wicks, Russell A.

2015-01-01

Purpose This study was performed to evaluate the linear distance accuracy and reliability of stitched small field of view (FOV) cone-beam computed tomography (CBCT) reconstructed images for the fabrication of implant surgical guides. Materials and Methods Three gutta percha points were fixed on the inferior border of a cadaveric mandible to serve as control reference points. Ten additional gutta percha points, representing fiduciary markers, were scattered on the buccal and lingual cortices at the level of the proposed complete denture flange. A digital caliper was used to measure the distance between the reference points and fiduciary markers, which represented the anatomic linear dimension. The mandible was scanned using small FOV CBCT, and the images were then reconstructed and stitched using the manufacturer's imaging software. The same measurements were then taken with the CBCT software. Results The anatomic linear dimension measurements and stitched small FOV CBCT measurements were statistically evaluated for linear accuracy. The mean difference between the anatomic linear dimension measurements and the stitched small FOV CBCT measurements was found to be 0.34 mm with a 95% confidence interval of +0.24 - +0.44 mm and a mean standard deviation of 0.30 mm. The difference between the control and the stitched small FOV CBCT measurements was insignificant within the parameters defined by this study. Conclusion The proven accuracy of stitched small FOV CBCT data sets may allow image-guided fabrication of implant surgical stents from such data sets. PMID:25793182

Identification among morphologically similar Argyreia (Convolvulaceae) based on leaf anatomy and phenetic analyses.

PubMed

Traiperm, Paweena; Chow, Janene; Nopun, Possathorn; Staples, G; Swangpol, Sasivimon C

2017-12-01

The genus Argyreia Lour. is one of the species-rich Asian genera in the family Convolvulaceae. Several species complexes were recognized in which taxon delimitation was imprecise, especially when examining herbarium materials without fully developed open flowers. The main goal of this study is to investigate and describe leaf anatomy for some morphologically similar Argyreia using epidermal peeling, leaf and petiole transverse sections, and scanning electron microscopy. Phenetic analyses including cluster analysis and principal component analysis were used to investigate the similarity of these morpho-types. Anatomical differences observed between the morpho-types include epidermal cell walls and the trichome types on the leaf epidermis. Additional differences in the leaf and petiole transverse sections include the epidermal cell shape of the adaxial leaf blade, the leaf margins, and the petiole transverse sectional outline. The phenogram from cluster analysis using the UPGMA method represented four groups with an R value of 0.87. Moreover, the important quantitative and qualitative leaf anatomical traits of the four groups were confirmed by the principal component analysis of the first two components. The results from phenetic analyses confirmed the anatomical differentiation between the morpho-types. Leaf anatomical features regarded as particularly informative for morpho-type differentiation can be used to supplement macro morphological identification.

Measuring Brain Connectivity: Diffusion Tensor Imaging Validates Resting State Temporal Correlations

PubMed Central

Skudlarski, Pawel; Jagannathan, Kanchana; Calhoun, Vince D.; Hampson, Michelle; Skudlarska, Beata A.; Pearlson, Godfrey

2015-01-01

Diffusion tensor imaging (DTI) and resting state temporal correlations (RSTC) are two leading techniques for investigating the connectivity of the human brain. They have been widely used to investigate the strength of anatomical and functional connections between distant brain regions in healthy subjects, and in clinical populations. Though they are both based on magnetic resonance imaging (MRI) they have not yet been compared directly. In this work both techniques were employed to create global connectivity matrices covering the whole brain gray matter. This allowed for direct comparisons between functional connectivity measured by RSTC with anatomical connectivity quantified using DTI tractography. We found that connectivity matrices obtained using both techniques showed significant agreement. Connectivity maps created for a priori defined anatomical regions showed significant correlation, and furthermore agreement was especially high in regions showing strong overall connectivity, such as those belonging to the default mode network. Direct comparison between functional RSTC and anatomical DTI connectivity, presented here for the first time, links two powerful approaches for investigating brain connectivity and shows their strong agreement. It provides a crucial multi-modal validation for resting state correlations as representing neuronal connectivity. The combination of both techniques presented here allows for further combining them to provide richer representation of brain connectivity both in the healthy brain and in clinical conditions. PMID:18771736

Measuring brain connectivity: diffusion tensor imaging validates resting state temporal correlations.

PubMed

Skudlarski, Pawel; Jagannathan, Kanchana; Calhoun, Vince D; Hampson, Michelle; Skudlarska, Beata A; Pearlson, Godfrey

2008-11-15

Diffusion tensor imaging (DTI) and resting state temporal correlations (RSTC) are two leading techniques for investigating the connectivity of the human brain. They have been widely used to investigate the strength of anatomical and functional connections between distant brain regions in healthy subjects, and in clinical populations. Though they are both based on magnetic resonance imaging (MRI) they have not yet been compared directly. In this work both techniques were employed to create global connectivity matrices covering the whole brain gray matter. This allowed for direct comparisons between functional connectivity measured by RSTC with anatomical connectivity quantified using DTI tractography. We found that connectivity matrices obtained using both techniques showed significant agreement. Connectivity maps created for a priori defined anatomical regions showed significant correlation, and furthermore agreement was especially high in regions showing strong overall connectivity, such as those belonging to the default mode network. Direct comparison between functional RSTC and anatomical DTI connectivity, presented here for the first time, links two powerful approaches for investigating brain connectivity and shows their strong agreement. It provides a crucial multi-modal validation for resting state correlations as representing neuronal connectivity. The combination of both techniques presented here allows for further combining them to provide richer representation of brain connectivity both in the healthy brain and in clinical conditions.

Transcriptomic and anatomical complexity of primary, seminal, and crown roots highlight root type-specific functional diversity in maize (Zea mays L.)

PubMed Central

Tai, Huanhuan; Lu, Xin; Opitz, Nina; Marcon, Caroline; Paschold, Anja; Lithio, Andrew; Nettleton, Dan; Hochholdinger, Frank

2016-01-01

Maize develops a complex root system composed of embryonic and post-embryonic roots. Spatio-temporal differences in the formation of these root types imply specific functions during maize development. A comparative transcriptomic study of embryonic primary and seminal, and post-embryonic crown roots of the maize inbred line B73 by RNA sequencing along with anatomical studies were conducted early in development. Seminal roots displayed unique anatomical features, whereas the organization of primary and crown roots was similar. For instance, seminal roots displayed fewer cortical cell files and their stele contained more meta-xylem vessels. Global expression profiling revealed diverse patterns of gene activity across all root types and highlighted the unique transcriptome of seminal roots. While functions in cell remodeling and cell wall formation were prominent in primary and crown roots, stress-related genes and transcriptional regulators were over-represented in seminal roots, suggesting functional specialization of the different root types. Dynamic expression of lignin biosynthesis genes and histochemical staining suggested diversification of cell wall lignification among the three root types. Our findings highlight a cost-efficient anatomical structure and a unique expression profile of seminal roots of the maize inbred line B73 different from primary and crown roots. PMID:26628518

Magnetic Resonance Imaging of Three-Dimensional Cervical Anatomy in the Second and Third Trimester

PubMed Central

HOUSE, Michael; BHADELIA, Rafeeque A.; MYERS, Kristin; SOCRATE, Simona

2009-01-01

OBJECTIVE Although a short cervix is known to be associated with preterm birth, the patterns of three-dimensional, anatomic changes leading to a short cervix are unknown. Our objective was to 1) construct three-dimensional anatomic models during normal pregnancy and 2) use the models to compare cervical anatomy in the second and third trimester. STUDY DESIGN A cross sectional study was performed in a population of patients referred to magnetic resonance imaging (MRI) for a fetal indication. Using magnetic resonance images for guidance, three-dimensional solid models of the following anatomic structures were constructed: amniotic cavity, uterine wall, cervical stroma, cervical mucosa and anterior vaginal wall. To compare cervical anatomy in the second and third trimester, models were matched according the size of the bony pelvis. RESULTS Fourteen patients were imaged and divided into two groups according to gestational age: 20 – 24 weeks (n=7)) and 31 – 36 weeks (n=7). Compared to the second trimester, the third trimester was associated with significant descent of the amniotic sac. (p=.02). Descent of the amniotic sac was associated with modified anatomy of the uterocervical junction. These 3-dimensional changes were associated with a cervix that appeared shorter in the third trimester. CONCLUSION We report a technique for constructing MRI-based, three-dimensional anatomic models during pregnancy. Compared to the second trimester, the third trimester is associated with three-dimensional changes in the cervix and lower uterine segment. PMID:19297070

Pathology economic model tool: a novel approach to workflow and budget cost analysis in an anatomic pathology laboratory.

PubMed

Muirhead, David; Aoun, Patricia; Powell, Michael; Juncker, Flemming; Mollerup, Jens

2010-08-01

The need for higher efficiency, maximum quality, and faster turnaround time is a continuous focus for anatomic pathology laboratories and drives changes in work scheduling, instrumentation, and management control systems. To determine the costs of generating routine, special, and immunohistochemical microscopic slides in a large, academic anatomic pathology laboratory using a top-down approach. The Pathology Economic Model Tool was used to analyze workflow processes at The Nebraska Medical Center's anatomic pathology laboratory. Data from the analysis were used to generate complete cost estimates, which included not only materials, consumables, and instrumentation but also specific labor and overhead components for each of the laboratory's subareas. The cost data generated by the Pathology Economic Model Tool were compared with the cost estimates generated using relative value units. Despite the use of automated systems for different processes, the workflow in the laboratory was found to be relatively labor intensive. The effect of labor and overhead on per-slide costs was significantly underestimated by traditional relative-value unit calculations when compared with the Pathology Economic Model Tool. Specific workflow defects with significant contributions to the cost per slide were identified. The cost of providing routine, special, and immunohistochemical slides may be significantly underestimated by traditional methods that rely on relative value units. Furthermore, a comprehensive analysis may identify specific workflow processes requiring improvement.

Why Can’t Rodents Vomit? A Comparative Behavioral, Anatomical, and Physiological Study

PubMed Central

Horn, Charles C.; Kimball, Bruce A.; Wang, Hong; Kaus, James; Dienel, Samuel; Nagy, Allysa; Gathright, Gordon R.; Yates, Bill J.; Andrews, Paul L. R.

2013-01-01

The vomiting (emetic) reflex is documented in numerous mammalian species, including primates and carnivores, yet laboratory rats and mice appear to lack this response. It is unclear whether these rodents do not vomit because of anatomical constraints (e.g., a relatively long abdominal esophagus) or lack of key neural circuits. Moreover, it is unknown whether laboratory rodents are representative of Rodentia with regards to this reflex. Here we conducted behavioral testing of members of all three major groups of Rodentia; mouse-related (rat, mouse, vole, beaver), Ctenohystrica (guinea pig, nutria), and squirrel-related (mountain beaver) species. Prototypical emetic agents, apomorphine (sc), veratrine (sc), and copper sulfate (ig), failed to produce either retching or vomiting in these species (although other behavioral effects, e.g., locomotion, were noted). These rodents also had anatomical constraints, which could limit the efficiency of vomiting should it be attempted, including reduced muscularity of the diaphragm and stomach geometry that is not well structured for moving contents towards the esophagus compared to species that can vomit (cat, ferret, and musk shrew). Lastly, an in situ brainstem preparation was used to make sensitive measures of mouth, esophagus, and shoulder muscular movements, and phrenic nerve activity–key features of emetic episodes. Laboratory mice and rats failed to display any of the common coordinated actions of these indices after typical emetic stimulation (resiniferatoxin and vagal afferent stimulation) compared to musk shrews. Overall the results suggest that the inability to vomit is a general property of Rodentia and that an absent brainstem neurological component is the most likely cause. The implications of these findings for the utility of rodents as models in the area of emesis research are discussed. PMID:23593236

Aligning Microtomography Analysis with Traditional Anatomy for a 3D Understanding of the Host-Parasite Interface – Phoradendron spp. Case Study

PubMed Central

Teixeira-Costa, Luíza; Ceccantini, Gregório C. T.

2016-01-01

The complex endophytic structure formed by parasitic plant species often represents a challenge in the study of the host-parasite interface. Even with the large amounts of anatomical slides, a three-dimensional comprehension of the structure may still be difficult to obtain. In the present study we applied the High Resolution X-ray Computed Tomography (HRXCT) analysis along with usual plant anatomy techniques in order to compare the infestation pattern of two mistletoe species of the genus Phoradendron. Additionally, we tested the use of contrasting solutions in order to improve the detection of the parasite’s endophytic tissue. To our knowledge, this is the first study to show the three-dimensional structure of host-mistletoe interface by using HRXCT technique. Results showed that Phoradendron perrottetii growing on the host Tapirira guianensis forms small woody galls with a restricted endophytic system. The sinkers were short and eventually grouped creating a continuous interface with the host wood. On the other hand, the long sinkers of P. bathyoryctum penetrate deeply into the wood of Cedrela fissilis branching in all directions throughout the woody gall area, forming a spread-out infestation pattern. The results indicate that the HRXCT is indeed a powerful approach to understand the endophytic system of parasitic plants. The combination of three-dimensional models of the infestation with anatomical analysis provided a broader understanding of the host-parasite connection. Unique anatomic features are reported for the sinkes of P. perrottetii, while the endophytic tissue of P. bathyoryctum conformed to general anatomy observed for other species of this genus. These differences are hypothesized to be related to the three-dimensional structure of each endophytic system and the communication stablished with the host. PMID:27630661

Indexing Anatomical Phrases in Neuro-Radiology Reports to the UMLS 2005AA

PubMed Central

Bashyam, Vijayaraghavan; Taira, Ricky K.

2005-01-01

This work describes a methodology to index anatomical phrases to the 2005AA release of the Unified Medical Language System (UMLS). A phrase chunking tool based on Natural Language Processing (NLP) was developed to identify semantically coherent phrases within medical reports. Using this phrase chunker, a set of 2,551 unique anatomical phrases was extracted from brain radiology reports. These phrases were mapped to the 2005AA release of the UMLS using a vector space model. Precision for the task of indexing unique phrases was 0.87. PMID:16778995

Mathematical modelling of intra-aortic balloon pump.

PubMed

Abdolrazaghi, Mona; Navidbakhsh, Mahdi; Hassani, Kamran

2010-10-01

Ischemic heart diseases now afflict thousands of Iranians and are the major cause of death in many industrialised countries. Mathematical modelling of an intra-aortic balloon pump (IABP) could provide a better understanding of its performance and help to represent blood flow and pressure in systemic arteries before and after inserting the pump. A mathematical modelling of the whole cardiovascular system was formulated using MATLAB software. The block diagram of the model consists of 43 compartments. All the anatomical data was extracted from the physiological references. In the next stage, myocardial infarction (MI) was induced in the model by decreasing the contractility of the left ventricle. The IABP was mathematically modelled and inserted in the model in the thoracic aorta I artery just before the descending aorta. The effects of IABP on MI were studied using the mathematical model. The normal operation of the cardiovascular system was studied firstly. The pressure-time graphs of the ventricles, atriums, aorta, pulmonary system, capillaries and arterioles were obtained. The volume-time curve of the left ventricle was also presented. The pressure-time curves of the left ventricle and thoracic aorta I were obtained for normal, MI, and inserted IABP conditions. Model verification was performed by comparing the simulation results with the clinical observations reported in the literature. IABP can be described by a theoretical model. Our model representing the cardiovascular system is capable of showing the effects of different pathologies such as MI and we have shown that MI effects can be reduced using IABP in accordance with the modelling results. The mathematical model should serve as a useful tool to simulate and better understand cardiovascular operation in normal and pathological conditions.

A 3D subject-specific model of the spinal subarachnoid space with anatomically realistic ventral and dorsal spinal cord nerve rootlets.

PubMed

Sass, Lucas R; Khani, Mohammadreza; Natividad, Gabryel Connely; Tubbs, R Shane; Baledent, Olivier; Martin, Bryn A

2017-12-19

The spinal subarachnoid space (SSS) has a complex 3D fluid-filled geometry with multiple levels of anatomic complexity, the most salient features being the spinal cord and dorsal and ventral nerve rootlets. An accurate anthropomorphic representation of these features is needed for development of in vitro and numerical models of cerebrospinal fluid (CSF) dynamics that can be used to inform and optimize CSF-based therapeutics. A subject-specific 3D model of the SSS was constructed based on high-resolution anatomic MRI. An expert operator completed manual segmentation of the CSF space with detailed consideration of the anatomy. 31 pairs of semi-idealized dorsal and ventral nerve rootlets (NR) were added to the model based on anatomic reference to the magnetic resonance (MR) imaging and cadaveric measurements in the literature. Key design criteria for each NR pair included the radicular line, descending angle, number of NR, attachment location along the spinal cord and exit through the dura mater. Model simplification and smoothing was performed to produce a final model with minimum vertices while maintaining minimum error between the original segmentation and final design. Final model geometry and hydrodynamics were characterized in terms of axial distribution of Reynolds number, Womersley number, hydraulic diameter, cross-sectional area and perimeter. The final model had a total of 139,901 vertices with a total CSF volume within the SSS of 97.3 cm 3 . Volume of the dura mater, spinal cord and NR was 123.1, 19.9 and 5.8 cm 3 . Surface area of these features was 318.52, 112.2 and 232.1 cm 2 respectively. Maximum Reynolds number was 174.9 and average Womersley number was 9.6, likely indicating presence of a laminar inertia-dominated oscillatory CSF flow field. This study details an anatomically realistic anthropomorphic 3D model of the SSS based on high-resolution MR imaging of a healthy human adult female. The model is provided for re-use under the Creative Commons Attribution-ShareAlike 4.0 International license (CC BY-SA 4.0) and can be used as a tool for development of in vitro and numerical models of CSF dynamics for design and optimization of intrathecal therapeutics.

Effects of Axial Torsion on Disc Height Distribution: An In Vivo Study.

PubMed

Espinoza Orías, Alejandro A; Mammoser, Nicole M; Triano, John J; An, Howard S; Andersson, Gunnar B J; Inoue, Nozomu

2016-05-01

Axial rotation of the torso is commonly used during manipulation treatment of low back pain. Little is known about the effect of these positions on disc morphology. Rotation is a three-dimensional event that is inadequately represented with planar images in the clinic. True quantification of the intervertebral gap can be achieved with a disc height distribution. The objective of this study was to analyze disc height distribution patterns during torsion relevant to manipulation in vivo. Eighty-one volunteers were computed tomography-scanned both in supine and in right 50° rotation positions. Virtual models of each intervertebral gap representing the disc were created with the inferior endplate of each "disc" set as the reference surface and separated into 5 anatomical zones: 4 peripheral and 1 central, corresponding to the footprint of the annulus fibrosus and nucleus pulposus, respectively. Whole-disc and individual anatomical zone disc height distributions were calculated in both positions and were compared against each other with analysis of variance, with significance set at P < .05. Mean neutral disc height was 7.32 mm (1.59 mm). With 50° rotation, a small but significant increase to 7.44 mm (1.52 mm) (P < .0002) was observed. The right side showed larger separation in most levels, except at L5/S1. The posterior and right zones increased in height upon axial rotation of the spine (P < .0001), whereas the left, anterior, and central decreased. This study quantified important tensile/compressive changes disc height during torsion. The implications of these mutually opposing changes on spinal manipulation are still unknown. Copyright © 2016 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.

Entrustable Professional Activities for Pathology

PubMed Central

Domen, Ronald E.; Conran, Richard M.; Hoffman, Robert D.; Post, Miriam D.; Brissette, Mark D.; Raciti, Patricia M.; Cohen, David A.; Roberts, Cory A.; Rojiani, Amyn M.; Kong, Christina S.; Peterson, Jo Elle G.; Johnson, Kristen; Plath, Sue; Powell, Suzanne Zein-Eldin

2017-01-01

Competency-based medical education has evolved over the past decades to include the Accreditation Council for Graduate Medical Education Accreditation System of resident evaluation based on the Milestones project. Entrustable professional activities represent another means to determine learner proficiency and evaluate educational outcomes in the workplace and training environment. The objective of this project was to develop entrustable professional activities for pathology graduate medical education encompassing primary anatomic and clinical pathology residency training. The Graduate Medical Education Committee of the College of American Pathologists met over the course of 2 years to identify and define entrustable professional activities for pathology graduate medical education. Nineteen entrustable professional activities were developed, including 7 for anatomic pathology, 4 for clinical pathology, and 8 that apply to both disciplines with 5 of these concerning laboratory management. The content defined for each entrustable professional activity includes the entrustable professional activity title, a description of the knowledge and skills required for competent performance, mapping to relevant Accreditation Council for Graduate Medical Education Milestone subcompetencies, and general assessment methods. Many critical activities that define the practice of pathology fit well within the entrustable professional activity model. The entrustable professional activities outlined by the Graduate Medical Education Committee are meant to provide an initial framework for the development of entrustable professional activity–related assessment and curricular tools for pathology residency training. PMID:28725792

An Interoceptive Predictive Coding Model of Conscious Presence

PubMed Central

Seth, Anil K.; Suzuki, Keisuke; Critchley, Hugo D.

2011-01-01

We describe a theoretical model of the neurocognitive mechanisms underlying conscious presence and its disturbances. The model is based on interoceptive prediction error and is informed by predictive models of agency, general models of hierarchical predictive coding and dopaminergic signaling in cortex, the role of the anterior insular cortex (AIC) in interoception and emotion, and cognitive neuroscience evidence from studies of virtual reality and of psychiatric disorders of presence, specifically depersonalization/derealization disorder. The model associates presence with successful suppression by top-down predictions of informative interoceptive signals evoked by autonomic control signals and, indirectly, by visceral responses to afferent sensory signals. The model connects presence to agency by allowing that predicted interoceptive signals will depend on whether afferent sensory signals are determined, by a parallel predictive-coding mechanism, to be self-generated or externally caused. Anatomically, we identify the AIC as the likely locus of key neural comparator mechanisms. Our model integrates a broad range of previously disparate evidence, makes predictions for conjoint manipulations of agency and presence, offers a new view of emotion as interoceptive inference, and represents a step toward a mechanistic account of a fundamental phenomenological property of consciousness. PMID:22291673

Do the skills acquired by novice surgeons using anatomic dry models transfer effectively to the task of diagnostic knee arthroscopy performed on cadaveric specimens?

PubMed

Butler, Aaron; Olson, Tyson; Koehler, Ryan; Nicandri, Gregg

2013-02-06

The use of surgical simulation in orthopaedic education is increasing; however, its ideal place within the training curriculum remains unknown. The purpose of this study was to determine the effectiveness of training novice surgeons on an anatomic dry model of the knee prior to training them to perform diagnostic arthroscopy on cadaveric specimens. Fourteen medical students were randomly assigned to two groups. The experimental group was trained to perform diagnostic arthroscopy of the knee on anatomic dry models prior to training on cadaveric specimens. The control group was trained only on cadaveric specimens. Proficiency was assessed with use of a modified version of a previously validated objective assessment of arthroscopic skill, the Basic Arthroscopic Knee Skill Scoring System (BAKSSS). The mean number of trials required to attain minimal proficiency when performing diagnostic knee arthroscopy was compared between the groups. The cumulative transfer effectiveness ratio (CTER) was calculated to measure the transfer of skills acquired by the experimental group. The mean number of trials to demonstrate minimum proficiency was significantly lower in the experimental group (2.57) than in the control group (4.57) (p < 0.01). The mean time to demonstrate proficiency was also significantly less in the experimental group (37.51 minutes) than in the control group (60.48 minutes) (p < 0.01). The CTER of dry-model training for the task of performing diagnostic knee arthroscopy on cadaveric specimens was 0.2. Previous training utilizing an anatomic dry knee model resulted in improved proficiency for novice surgeons learning to perform diagnostic knee arthroscopy on cadaveric specimens. A CTER of 0.2 suggests that dry models can serve as a useful adjunct to cadaveric training for diagnostic knee arthroscopy but cannot entirely replace it within the orthopaedic curriculum. Further work is necessary to determine the optimal amount of training on anatomic dry models that will maximize transfer effectiveness and to determine how well skills obtained in the simulated environment transfer to the operating room.

Tradition or change? Sources of body procurement for the Anatomical Institute of the University of Cologne in the Third Reich.

PubMed

Kaiser, Stephanie

2013-10-01

While it is known that all German anatomical institutes that have been examined made use of the bodies of victims of the National Socialist (NS) regime for teaching and research between 1933 and 1945, detailed investigations on many institutions are still missing. Among these is the anatomical institute of the University of Cologne. This university was the first university to voluntarily self-align with the policies of the new regime and was therefore often called a 'model NS university'. In addition, Cologne was the site of a NS special court and a central place for executions. Based on archival sources, this study investigates the interaction between the anatomical institute of the University of Cologne with the NS authorities and the origin of the body supply for dissection and research. The documents reveal that the institute continued to receive bodies from traditional sources like the public morgue and hospitals, but with the beginning of World War II (WWII) an increasing amount of bodies of victims of the NS regime became available. Thus, the anatomical institute of Cologne collaborated and benefited from the policies of the NS regime, especially during WWII, like all other already explored anatomical institutes in Germany to varying degrees. © 2013 Anatomical Society.

Clay modeling versus written modules as effective interventions in understanding human anatomy.

PubMed

Bareither, Mary Lou; Arbel, Vered; Growe, Meghan; Muszczynski, Emily; Rudd, Adam; Marone, Jane R

2013-01-01

The effectiveness of clay modeling to written modules is examined to determine the degree of improvement in learning and retention of anatomical 3D relationships among students with different learning preferences. Thirty-nine undergraduate students enrolled in a cadaver dissection course completed a pre-assessment examination and the VARK questionnaire, classifying learning preference as visual, auditory, read/write, or kinesthetic. Students were divided into clay, module, and control groups with preference for learning style distributed among groups. The clay and module groups participated in weekly one-hour classes using either clay models or answering written questions (modules) about anatomical relationships, respectively. The control group received no intervention. Post-assessment and retention examinations were administered at the end of the semester, and three months later, respectively. Two variables (Δ1, Δ2) represented examination score differences between pre- and post-assessment and between post-assessment and retention examinations, respectively. The Δ1 for clay and module groups were each significantly higher than controls (21.46 ± 8.2 vs. 15.70 ± 7.5, P ≤ 0.05; and 21.31 ± 6.9 vs. 15.70 ± 7.5, P ≤0.05, respectively). The Δ2 for clay and module groups approached but did not achieve significance over controls (-6.09 ± 5.07 vs. -8.80 ± 4.60, P = 0.16 and -5.73 ± 4.47 vs. -8.80 ± 4.60, P = 0.12, respectively). No significant differences were seen between interventions or learning preferences in any group. However, students of some learning styles tended to perform better when engaging in certain modalities. Multiple teaching modalities may accommodate learning preferences and improve understanding of anatomy. Copyright © 2012 American Association of Anatomists.

Marginal hepatectomy in the rat: from anatomy to surgery.

PubMed

Madrahimov, Nodir; Dirsch, Olaf; Broelsch, Christoph; Dahmen, Uta

2006-07-01

Based on the 3-dimensional visualization of vascular supply and drainage, a vessel-oriented resection technique was optimized. The new surgical technique was used to determine the maximal reduction in liver mass enabling a 50% 1-week survival rate. Determination of the minimal liver mass is necessary in clinical as well as in experimental liver surgery. In rats, survival seems to depend on the surgical technique applied. Extended hepatectomy with removal of 90% of the liver mass was long regarded as a lethal model. Introduction of a vessel-oriented approach enabled long-term survival in this model. The lobar and vascular anatomy of rat livers was visualized by plastination of the whole organ, respectively, by corrosion casts of the portal vein, hepatic artery and liver veins. The three-dimensional models were used to extract the underlying anatomic structure. In 90% partial hepatectomy, the liver parenchyma was clamped close to the base of the respective liver lobes (left lateral, median and right, liver lobe). Piercing sutures were placed through the liver parenchyma, so that the stem of portal vein and the accompanying hepatic artery but also the hepatic vein were included. A 1-week survival rate of 100% was achieved after 90% hepatectomy. Extending the procedure to 95% resection by additional removal of the upper caudate lobe led to a 1-week survival rate of 66%; 97% partial hepatectomy, accomplished by additional resection of the lower caudate lobe only leaving the paracaval parts of the liver behind, resulted in 100% lethality within 4 days. Using a anatomically based, vessel-oriented, parenchyma-preserving surgical technique in 95% liver resections led to long-term survival. This represents the maximal reduction of liver mass compatible with survival.

Pig lumbar spine anatomy and imaging-guided lateral lumbar puncture: a new large animal model for intrathecal drug delivery.

PubMed

Pleticha, Josef; Maus, Timothy P; Jeng-Singh, Christian; Marsh, Michael P; Al-Saiegh, Fadi; Christner, Jodie A; Lee, Kendall H; Beutler, Andreas S

2013-05-30

Intrathecal (IT) administration is an important route of drug delivery, and its modelling in a large animal species is of critical value. Although domestic swine is the preferred species for preclinical pharmacology, no minimally invasive method has been established to deliver agents into the IT space. While a "blind" lumbar puncture (LP) can sample cerebrospinal fluid (CSF), it is unreliable for drug delivery in pigs. Using computed tomography (CT), we determined the underlying anatomical reasons for this irregularity. The pig spinal cord was visualised terminating at the S2-S3 level. The lumbar region contained only small amounts of CSF found in the lateral recess. Additional anatomical constraints included ossification of the midline ligaments, overlapping lamina with small interlaminar spaces, and a large bulk of epidural adipose tissue. Accommodating the the pig CT anatomy, we developed a lateral LP (LLP) injection technique that employs advanced planning of the needle path and monitoring of the IT injection progress. The key features of the LLP procedure involved choosing a vertebral level without overlapping lamina or spinal ligament ossification, a needle trajectory crossing the midline, and entering the IT space in its lateral recess. Effective IT delivery was validated by the injection of contrast media to obtain a CT myelogram. LLP represents a safe and reliable method to deliver agents to the lumbar pig IT space, which can be implemented in a straightforward way by any laboratory with access to CT equipment. Therefore, LLP is an attractive large animal model for preclinical studies of IT therapies. Copyright © 2013 Elsevier B.V. All rights reserved.

Feature-Based Morphometry: Discovering Group-related Anatomical Patterns

PubMed Central

Toews, Matthew; Wells, William; Collins, D. Louis; Arbel, Tal

2015-01-01

This paper presents feature-based morphometry (FBM), a new, fully data-driven technique for discovering patterns of group-related anatomical structure in volumetric imagery. In contrast to most morphometry methods which assume one-to-one correspondence between subjects, FBM explicitly aims to identify distinctive anatomical patterns that may only be present in subsets of subjects, due to disease or anatomical variability. The image is modeled as a collage of generic, localized image features that need not be present in all subjects. Scale-space theory is applied to analyze image features at the characteristic scale of underlying anatomical structures, instead of at arbitrary scales such as global or voxel-level. A probabilistic model describes features in terms of their appearance, geometry, and relationship to subject groups, and is automatically learned from a set of subject images and group labels. Features resulting from learning correspond to group-related anatomical structures that can potentially be used as image biomarkers of disease or as a basis for computer-aided diagnosis. The relationship between features and groups is quantified by the likelihood of feature occurrence within a specific group vs. the rest of the population, and feature significance is quantified in terms of the false discovery rate. Experiments validate FBM clinically in the analysis of normal (NC) and Alzheimer's (AD) brain images using the freely available OASIS database. FBM automatically identifies known structural differences between NC and AD subjects in a fully data-driven fashion, and an equal error classification rate of 0.80 is achieved for subjects aged 60-80 years exhibiting mild AD (CDR=1). PMID:19853047

The importance of being Florentine: a journey around the world for wax anatomical Venuses.

PubMed

de Ceglia, Francesco Paolo

2011-01-01

This article reconstructs the 19th century history of events regarding a few female wax anatomical models made in Florence. More or less faithful copies of those housed in Florence's Museum of Physics and Natural History, these models were destined for display in temporary exhibitions. In their travels through Europe and the United States, they transformed the expression "Florentine Venus" into a sort of brand name used to label and offer respectability to pieces of widely varying quality.

A set of 4D pediatric XCAT reference phantoms for multimodality research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Norris, Hannah, E-mail: Hannah.norris@duke.edu; Zhang, Yakun; Bond, Jason

Purpose: The authors previously developed an adult population of 4D extended cardiac-torso (XCAT) phantoms for multimodality imaging research. In this work, the authors develop a reference set of 4D pediatric XCAT phantoms consisting of male and female anatomies at ages of newborn, 1, 5, 10, and 15 years. These models will serve as the foundation from which the authors will create a vast population of pediatric phantoms for optimizing pediatric CT imaging protocols. Methods: Each phantom was based on a unique set of CT data from a normal patient obtained from the Duke University database. The datasets were selected tomore » best match the reference values for height and weight for the different ages and genders according to ICRP Publication 89. The major organs and structures were segmented from the CT data and used to create an initial pediatric model defined using nonuniform rational B-spline surfaces. The CT data covered the entire torso and part of the head. To complete the body, the authors manually added on the top of the head and the arms and legs using scaled versions of the XCAT adult models or additional models created from cadaver data. A multichannel large deformation diffeomorphic metric mapping algorithm was then used to calculate the transform from a template XCAT phantom (male or female 50th percentile adult) to the target pediatric model. The transform was applied to the template XCAT to fill in any unsegmented structures within the target phantom and to implement the 4D cardiac and respiratory models in the new anatomy. The masses of the organs in each phantom were matched to the reference values given in ICRP Publication 89. The new reference models were checked for anatomical accuracy via visual inspection. Results: The authors created a set of ten pediatric reference phantoms that have the same level of detail and functionality as the original XCAT phantom adults. Each consists of thousands of anatomical structures and includes parameterized models for the cardiac and respiratory motions. Based on patient data, the phantoms capture the anatomic variations of childhood, such as the development of bone in the skull, pelvis, and long bones, and the growth of the vertebrae and organs. The phantoms can be combined with existing simulation packages to generate realistic pediatric imaging data from different modalities. Conclusions: The development of patient-derived pediatric computational phantoms is useful in providing variable anatomies for simulation. Future work will expand this ten-phantom base to a host of pediatric phantoms representative of the public at large. This can provide a means to evaluate and improve pediatric imaging devices and to optimize CT protocols in terms of image quality and radiation dose.« less

Simplified three-dimensional model provides anatomical insights in lizards' caudal autotomy as printed illustration.

PubMed

De Amorim, Joana D C G; Travnik, Isadora; De Sousa, Bernadete M

2015-03-01

Lizards' caudal autotomy is a complex and vastly employed antipredator mechanism, with thorough anatomic adaptations involved. Due to its diminished size and intricate structures, vertebral anatomy is hard to be clearly conveyed to students and researchers of other areas. Three-dimensional models are prodigious tools in unveiling anatomical nuances. Some of the techniques used to create them can produce irregular and complicated forms, which despite being very accurate, lack didactical uniformity and simplicity. Since both are considered fundamental characteristics for comprehension, a simplified model could be the key to improve learning. The model here presented depicts the caudal osteology of Tropidurus itambere, and was designed to be concise, in order to be easily assimilated, yet complete, not to compromise the informative aspect. The creation process requires only basic skills in manipulating polygons in 3D modeling softwares, in addition to the appropriate knowledge of the structure to be modeled. As reference for the modeling, we used microscopic observation and a photograph database of the caudal structures. This way, no advanced laboratory equipment was needed and all biological materials were preserved for future research. Therefore, we propose a wider usage of simplified 3D models both in the classroom and as illustrations for scientific publications.