Segmentation of liver, its vessels and lesions from CT images for surgical planning

<p>Abstract</p> <p>Background</p> <p>Cancer treatments are complex and involve different actions, which include many times a surgical procedure. Medical imaging provides important information for surgical planning, and it usually demands a proper segmentation, i.e., the identification of meaningful objects, such as organs and lesions. This study proposes a methodology to segment the liver, its vessels and nodules from computer tomography images for surgical planning.</p> <p>Methods</p> <p>The proposed methodology consists of four steps executed sequentially: segmentation of liver, segmentation of vessels and nodules, identification of hepatic and portal veins, and segmentation of Couinaud anatomical segments. Firstly, the liver is segmented by a method based on a deformable model implemented through level sets, of which parameters are adjusted by using a supervised optimization procedure. Secondly, a mixture model is used to segment nodules and vessels through a region growing process. Then, the identification of hepatic and portal veins is performed using liver anatomical knowledge and a vein tracking algorithm. Finally, the Couinaud anatomical segments are identified according to the anatomical liver model proposed by Couinaud.</p> <p>Results</p> <p>Experiments were conducted using data and metrics brought from the liver segmentation competition held in the Sliver07 conference. A subset of five exams was used for estimation of segmentation parameter values, while 15 exams were used for evaluation. The method attained a good performance in 17 of the 20 exams, being ranked as the 6^thbest semi-automatic method when comparing to the methods described on the Sliver07 website (2008). It attained visual consistent results for nodules and veins segmentation, and we compiled the results, showing the best, worst, and mean results for all dataset.</p> <p>Conclusions</p> <p>The method for liver segmentation performed well, according to the results of the numerical evaluation implemented, and the segmentation of liver internal structures were consistent with the anatomy of the liver, as confirmed by a specialist. The analysis provided evidences that the method to segment the liver may be applied to segment other organs, especially to those whose distribution of voxel intensities is nearly Gaussian shaped.</p

Magnetic Resonance Imaging and Gynecological Devices

Background: Performing magnetic resonance imaging (MRI) on women with gynecological devices is a completely accepted practice. The goal of our review is to assess how safe it is to perform MRI on women using contraceptive implants or devices. Study Design: Literature review, searching in PubMed-Medline/Ovid for the following keywords: magnetic resonance imaging, intrauterine devices, Implanon® and Essure®. Results: Though plastic devices do not represent a contraindication to the use of the technique, those including metallic components have been submitted to several tests, after which they were classified as MR Conditional (devices presenting no risks in MR-specific environments) by the Food and Drug Administration. Thus, the use of MRI can be safely advised to women with this type of device as long as the magnetic resonance equipment is ≤3.0 T. Conclusions: Presently, there is no scientific evidence that contraindicates performing MRI on women with any kind of gynecological device. Therefore, this procedure is safe as long as it is performed under previously tested conditions

Prescrição Inapropriada em Idosos numa Enfermaria de Medicina Interna

INTRODUCTION: Polypharmacy is often observed in elderly patients and is associated with an increased risk of adverse drug reactions, side effects and interactions. Clinicians should be alert to inappropriate drug prescribing and reduce polypharmacy. MATERIAL AND METHODS: Observational, longitudinal, retrospective and descriptive study in an internal medicine ward in a Portuguese hospital. Polypharmacy was defined as the use of five or more different medicines. The purpose of this study was to describe the prevalence of polypharmacy and inappropriate prescribing at admission and discharge in an internal medicine ward, according to deprescribing.org guidelines/algorithms. A total of 838 consecutive patients were admitted between January and July 2017. All patients were aged under 65 years old, and those who died before discharge were excluded. Patients' medications were reviewed from a medical database at hospital admission and discharge. We examined whether patients were taking anticoagulants, proton pump inhibitors, benzodiazepines, antipsychotics and/or antihyperglycemic medication. RESULTS: A total of 483 patients were included, mean age was 79.2 ± 8.0 years, and 42% of patients were male. Median number of medications at admission and discharge was six. Polypharmacy was present in more than 70% of admitted patients. Proton pump inhibitors were the most common inappropriate prescription at discharge (17.2%). DISCUSSION: This study demonstrated a low use of inappropriate medicine (11.2% - 17.2%) in older people discharged from hospital, when compared to other studies. CONCLUSION: Our study shows that polypharmacy is present in more than 70% of elderly admitted patients. Nevertheless, the drug inappropriateness rate was not significantly affected by polypharmacy at both admission and discharge, being overall lower than published data.Introdução: A polimedicação é observada nos doentes idosos e está associada a um maior risco de reações adversas, efeitos secundários e interações. Os clínicos devem atentos à prescrição inapropriada e à redução da polimedicação. Material e Métodos: Estudo observacional, longitudinal, retrospetivo e descritivo, realizado numa enfermaria de medicina interna num hospital português. Definimos a polimedicação como o uso de cinco ou mais medicamentos. O objetivo foi descrever a prevalência da polimedicação e a prescrição inapropriada, na admissão e alta, de acordo com as guidelines/algoritmos definidos em deprescribing. org. Admitimos 838 doentes entre janeiro e julho de 2017. Excluímos todos aqueles com idade inferior a 65 anos e óbitos. A medicação dos doentes foi revista a partir da base de dados hospitalar, à admissão e à data de alta. Examinámos se os doentes estavam a tomar anticoagulantes, inibidores da bomba de protões, benzodiazepinas, antipsicóticos e/ou anti hiperglicémicos. Resultados: Incluímos 483 doentes, com média de idade de 79,2 ± 8,0 anos, e 42% dos quais eram homens. A mediana da medicação à admissão e à alta foi seis. A polimedicação estava presente em mais de 70% dos doentes admitidos. Os inibidores da bomba de protões foram a classe mais inapropriadamente prescrita à data de alta (17,2%). Discussão: Demonstrámos um uso reduzido de fármacos inapropriados (11,2% - 17,2%) nos idosos, à alta hospitalar, quando comparado com outros estudos. Conclusão: Demonstrámos que a polimedicação estava presente em mais de 70% dos idosos admitidos. Contudo, a taxa de prescrição inapropriada não afetou significativamente a polimedicação na admissão e na alta, sendo inferior aos dados publicados.info:eu-repo/semantics/publishedVersio

Pleuroamniotic shunting--case report

Fetal hydrothorax refers to a collection of fluid within the fetal thorax that may be the result of chylous leak from the thoracic duct (primary hydrothorax) or generalized fluid retention associated with immune or no immune fetal hydrops (secondary hydrothorax). The authors' presents a case report occurred in 2002, of a pregnant woman that at 25 weeks' gestation that was referred to Maternidade Bissaya-Barreto-Coimbra because of a fetal hydrothorax at left, under tension and with cardiac decompensation signs. A fetal thoracocentesis was performed and the diagnosis was chylothorax. Because of a rapid reaccumulation of fluid a pleuroamniotic shunt was placed. The effusion and the cardiac decompensation signs regressed. The delivery was at 38 weeks' gestation. The newborn had been stable. Actually he has 10 months, is healthy and has a normal grow and development

Acute mastoiditis in children: Middle ear cultures may help in reducing use of broad spectrum antibiotics

Acute mastoiditis (AM) is a suppurative infection of the mastoid air cells, representing the most frequent complication of acute otitis media. AM remains an important entity in children due to its potential complications and sequelae. We aim to describe the cases of AM admitted at our department, identify risk factors potentially associated with complications and analyse the changes in clinical approach of AM over time. METHODS: Case review of clinical files of children admitted with acute mastoiditis from June 1996 to May 2013 at a Lisbon metropolitan area hospital. Data was divided into two groups (prior and after May 2005) in order to evaluate changes in AM approach over the years. RESULTS: 135 AM episodes were included. The median age was 3.8 years and 42% children were less than 24 months of age. Symptoms at presentation included fever (69%), ear pain (56%) and otorrhea (40%). Complications occurred in 22% patients and were more common in children under 24 months (33% vs 15%, p ≤ 0.01). Leukocyte count was significantly higher in children with complications (16.7 vs 14.5 × 109/μL, p ≤ 0.05) as was C-Reactive Protein value (13 vs 6.3 mg/dL, p ≤ 0.001). There was a significant association between the development of complications and C-Reactive Protein value at admission (OR 1.892; IC95%: 1.018-2.493, p ≤ 0.01). The optimal cut-off value was 7.21 mg/dL. Over time there was a significant increase in middle ear cultures obtained by tympanocentesis during surgery (2% vs 16%, p ≤ 0,01) and also a decrease in the use of broad spectrum antibiotherapy as initial treatment (52% vs 25%,p ≤ 0,001). CONCLUSIONS: Children under 24 months, with high leukocyte count or with high C-Reactive Protein value should be monitored closely since complications tend to be more frequent. A CRP value of 7.21 mg/dL at admission seems to be a good cut-off to monitor children for potential complications. Throughout the period analysed more cultures were performed allowing identification of the pathogens and implementation of appropriate antibiotic therapy.info:eu-repo/semantics/publishedVersio

Spherical perspective

We survey the present state of spherical perspective, regarding both mathematical structure and drawing practice, with a view to applications in the visual arts. We define a spherical perspective as the entailment of a conical anamorphosis with a compact flattening of the visual sphere. We examine a general framework for solving spherical perspectives, exemplified with the azimuthal equidistant (“fisheye”) and equirectangular cases. We consider the relation between spherical and curvilinear perspectives. We briefly discuss computer renderings but focus on methods adapted to freehand sketching or technical drawing with simple instruments such as ruler and compass. We discuss how handmade spherical perspective drawings can generate immersive anamorphoses, which can be rendered as virtual reality panoramas, leading to hybrid visual creations that bridge the gap between traditional drawing and digital environments.info:eu-repo/semantics/publishedVersio

Genome Diversity of Epstein-Barr Virus from Multiple Tumor Types and Normal Infection

Epstein-Barr virus (EBV) infects most of the world’s population and is causally associated with several human cancers, but little is known about how EBV genetic variation might influence infection or EBV-associated disease. There are currently no published wild-type EBV genome sequences from a healthy individual and very few genomes from EBV-associated diseases. We have sequenced 71 geographically distinct EBV strains from cell lines, multiple types of primary tumor, and blood samples and the first EBV genome from the saliva of a healthy carrier. We show that the established genome map of EBV accurately represents all strains sequenced, but novel deletions are present in a few isolates. We have increased the number of type 2 EBV genomes sequenced from one to 12 and establish that the type 1/type 2 classification is a major feature of EBV genome variation, defined almost exclusively by variation of EBNA2 and EBNA3 genes, but geographic variation is also present. Single nucleotide polymorphism (SNP) density varies substantially across all known open reading frames and is highest in latency-associated genes. Some T-cell epitope sequences in EBNA3 genes show extensive variation across strains, and we identify codons under positive selection, both important considerations for the development of vaccines and T-cell therapy. We also provide new evidence for recombination between strains, which provides a further mechanism for the generation of diversity. Our results provide the first global view of EBV sequence variation and demonstrate an effective method for sequencing large numbers of genomes to further understand the genetics of EBV infection

The E3 ubiquitin ligase SCF(Fbxo7) mediates proteasomal degradation of UXT isoform 2 (UXT-V2) to inhibit the NF-κB signaling pathway.

BACKGROUND: Ubiquitously eXpressed Transcript isoform 2 (UXTV2) is a prefoldin-like protein involved in NF-κB signaling, apoptosis, and the androgen and estrogen response. UXT-V2 is a cofactor in the NF-κB transcriptional enhanceosome, and its knockdown inhibits TNF-α -induced NF-κB activation. Fbxo7 is an F-box protein that interacts with SKP1, Cullin1 and RBX1 proteins to form an SCF(Fbxo7) E3 ubiquitin ligase complex. Fbxo7 negatively regulates NF-κB signaling through TRAF2 and cIAP1 ubiquitination. METHODS: We combine co-immunoprecipitation, ubiquitination in vitro and in vivo, cycloheximide chase assay, ubiquitin chain restriction analysis and microscopy to investigate interaction between Fbxo7 and overexpressed UXT-V2-HA. RESULTS: The Ubl domain of Fbxo7 contributes to interaction with UXTV2. This substrate is polyubiquitinated by SCF(Fbxo7) with K48 and K63 ubiquitin chain linkages in vitro and in vivo. This post-translational modification decreases UXT-V2 stability and promotes its proteasomal degradation. We further show that UXTV1, an alternatively spliced isoform of UXT, containing 12 additional amino acids at the N-terminus as compared to UXTV2, also interacts with and is ubiquitinated by Fbxo7. Moreover, FBXO7 knockdown promotes UXT-V2 accumulation, and the overexpression of Fbxo7-ΔF-box protects UXT-V2 from proteasomal degradation and enhances the responsiveness of NF-κB reporter. We find that UXT-V2 colocalizes with Fbxo7 in the cell nucleus. CONCLUSIONS: Together, our study reveals that SCF(Fbxo7) mediates the proteasomal degradation of UXT-V2 causing the inhibition of the NF-κB signaling pathway. GENERAL SIGNIFICANCE: Discovering new substrates of E3 ubiquitin-ligase SCF(Fbxo7) contributes to understand its function in different diseases such as cancer and Parkinson.Biotechnology and Biological Science Research Council [BB/J007846/1]

Movement Behavior of High-Heeled Walking: How Does the Nervous System Control the Ankle Joint during an Unstable Walking Condition?

The human locomotor system is flexible and enables humans to move without falling even under less than optimal conditions. Walking with high-heeled shoes constitutes an unstable condition and here we ask how the nervous system controls the ankle joint in this situation? We investigated the movement behavior of high-heeled and barefooted walking in eleven female subjects. The movement variability was quantified by calculation of approximate entropy (ApEn) in the ankle joint angle and the standard deviation (SD) of the stride time intervals. Electromyography (EMG) of the soleus (SO) and tibialis anterior (TA) muscles and the soleus Hoffmann (H-) reflex were measured at 4.0 km/h on a motor driven treadmill to reveal the underlying motor strategies in each walking condition. The ApEn of the ankle joint angle was significantly higher (p<0.01) during high-heeled (0.38±0.08) than during barefooted walking (0.28±0.07). During high-heeled walking, coactivation between the SO and TA muscles increased towards heel strike and the H-reflex was significantly increased in terminal swing by 40% (p<0.01). These observations show that high-heeled walking is characterized by a more complex and less predictable pattern than barefooted walking. Increased coactivation about the ankle joint together with increased excitability of the SO H-reflex in terminal swing phase indicates that the motor strategy was changed during high-heeled walking. Although, the participants were young, healthy and accustomed to high-heeled walking the results demonstrate that that walking on high-heels needs to be controlled differently from barefooted walking. We suggest that the higher variability reflects an adjusted neural strategy of the nervous system to control the ankle joint during high-heeled walking