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

Effects of 3-beta-diol, an androgen metabolite with intrinsic estrogen-like effects, in modulating the aquaporin-9 expression in the rat efferent ductules

BACKGROUND: Fluid homeostasis is critical for normal function of the male reproductive tract and aquaporins (AQP) play an important role in maintenance of this water and ion balance. Several AQPs have been identified in the male, but their regulation is not fully comprehended. Hormonal regulation of AQPs appears to be dependent on the steroid in the reproductive tract region. AQP9 displays unique hormonal regulation in the efferent ductules and epididymis, as it is regulated by both estrogen and dihydrotestosterone (DHT) in the efferent ductules, but only by DHT in the initial segment epididymis. Recent data have shown that a metabolite of DHT, 5-alpha-androstane-3-beta-17-beta-diol (3-beta-diol), once considered inactive, is also present in high concentrations in the male and indeed has biological activity. 3-beta-diol does not bind to the androgen receptor, but rather to estrogen receptors ER-alpha and ER-beta, with higher affinity for ER-beta. The existence of this estrogenic DHT metabolite has raised the possibility that estradiol may not be the only estrogen to play a major role in the male reproductive system. Considering that both ER-alpha and ER-beta are highly expressed in efferent ductules, we hypothesized that the DHT regulation of AQP9 could be due to the 3-beta-diol metabolite. METHODS: To test this hypothesis, adult male rats were submitted to surgical castration followed by estradiol, DHT or 3-beta-diol replacement. Changes in AQP9 expression in the efferent ductules were investigated by using immunohistochemistry and Western blotting assay. RESULTS: Data show that, after castration, AQP9 expression was significantly reduced in the efferent ductules. 3-beta-diol injections restored AQP9 expression, similar to DHT and estradiol. The results were confirmed by Western blotting assay. CONCLUSION: This is the first evidence that 3-beta-diol has biological activity in the male reproductive tract and that this androgen metabolite has estrogen-like activity in the efferent ductules, whose major function is the reabsorption of luminal fluid

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

Externally validated model predicting gait independence after stroke showed fair performance and improved after updating

ObjectiveTo externally validate recent prognostic models that predict independent gait following stroke.Study design and settingA systematic search identified recent models (ResultsThree prognostic models met our criteria, all with high Risk of Bias. Validation data was only available for the Australian model. This model used National Institute of Health Stroke Scale (NIHSS) and age to predict independent gait, using Motor Assessment Scale (MAS) walking item. For validation, Scandinavian Stroke Scale (SSS) was a proxy for NIHSS, and Functional Independence Measure (FIM) locomotion item was a proxy for MAS. The Area Under the Curve was 0.77 (0.74-0.80) and had good calibration in the validation dataset. Adjustment of the intercept and regression coefficients slightly improved discrimination. By adding paretic leg strength, the model further improved (AUC 0.82).ConclusionExternal validation of the Australian model with proxies showed fair discrimination and good calibration. Updating the model by adding paretic leg strength further improved model performance

Neuro-Behçet: a clinical exercise

Behçet disease is a recurrent systemic vasculitis of unknown etiology, that involves vessels of nearly all sizes and types. Because of this, disease manifestations can occur at many sites throughout the body. Central nervous system (CNS) involvement may be parenchymal or nonparenchymal and has a global prevalence that ranges from 3% to 10%. Main signs of CNS involvement are pyramidal and those resulting from brain stem lesions. Aseptic meningitis, mental changes, sphincter disturbances, pseudobulbar syndrome, and deep sensory abnormalities may be seen. Analysis of cerebrospinal fluid, computed tomography (CT), magnetic resonance imaging (MRI), single-photon emission computed tomography (SPECT) and brain angiography offer assistance in the diagnosis. The course of disease can be primary progressive, secondary progressive or have a relapsing-remitting profile. Boluses of methylprednisolone for three days followed by cyclophosphamide are the treatment of choice. This papers discusses these aspects of neuro-Behcet on the basis of complex clinical cas

Hypoglycemia in elderly diabetic patients: experience in a diabetes unit

Introdução: Assiste-se atualmente a uma evolução paralela do envelhecimento da população e da prevalência crescente de Diabetes Mellitus. Os indivíduos idosos estão particularmente susceptíveis à ocorrência de episódios de hipoglicemia, responsáveis por uma morbimortalidade significativa nesta população. Os objetivos do estudo foram a avaliação da incidência de doentes diabéticos com episódios de hipoglicemia na população de idosos seguidos na Unidade Integrada de Diabetes (UID) do HFF e caracterizar, comparativamente, a população de idosos com e sem episódios de hipoglicemia. Materiais e métodos: Estudo observacional, longitudinal, retrospetivo, descritivo, consistindo na análise de variáveis demográficas, clínicas e laboratoriais constantes em processo clínico informático Soarian®, num período de um ano, procedendo-se a análise estatística dos mesmos. Resultados: Em 2013 mais de metade dos doentes seguidos na UID eram idosos, tendo-se verificado episódios de hipoglicemia em 22,6%. A maioria dos doentes com episódios de hipoglicemia (CH) tratava-se de doentes com mais de 75 anos e tinha um tempo de evolução de doença superior a 5 anos, com uma média de tempo de evolução de 17,5 anos. A presença de complicações microvasculares foi objetivada em mais de metade destes doentes (51,2%) sendo que 47,8% apresentavam complicações macrovasculares. A HbA1C média era de 7,8%, tendo apresentado, ao longo do ano, uma descida média de 0,6%. A maioria (71,7%) dos doentes CH estava medicado com insulina, mais de metade destes (54,3%) medicados com insulina com pico de ação, tratando-se de proporções significativamente superiores às objetivadas nos doentes sem episódios de hipoglicemia (SH). Relativamente ao uso de antidiabéticos orais, 26,1% estavam medicados com sulfonilureias. Conclusão: Este estudo vem reiterar a necessidade de individualização e adequação de objetivos de cuidados na população idosa e com mais comorbilidades, assumindo alvos glicémicos mais permissivos e esquemas terapêuticos com menor risco associado de hipoglicemia.info:eu-repo/semantics/publishedVersio

Microfluidic systems for the analysis of the viscoelastic fluid flow phenomena in porous media

In this study, two microfluidic devices are proposed as simplified 1-D microfluidic analogues of a porous medium. The objectives are twofold: firstly to assess the usefulness of the microchannels to mimic the porous medium in a controlled and simplified manner, and secondly to obtain a better insight about the flow characteristics of viscoelastic fluids flowing through a packed bed. For these purposes, flow visualizations and pressure drop measurements are conducted with Newtonian and viscoelastic fluids. The 1-D microfluidic analogues of porous medium consisted of microchannels with a sequence of contractions/ expansions disposed in symmetric and asymmetric arrangements. The real porous medium is in reality, a complex combination of the two arrangements of particles simulated with the microchannels, which can be considered as limiting ideal configurations. The results show that both configurations are able to mimic well the pressure drop variation with flow rate for Newtonian fluids. However, due to the intrinsic differences in the deformation rate profiles associated with each microgeometry, the symmetric configuration is more suitable for studying the flow of viscoelastic fluids at low De values, while the asymmetric configuration provides better results at high De values. In this way, both microgeometries seem to be complementary and could be interesting tools to obtain a better insight about the flow of viscoelastic fluids through a porous medium. Such model systems could be very interesting to use in polymer-flood processes for enhanced oil recovery, for instance, as a tool for selecting the most suitable viscoelastic fluid to be used in a specific formation. The selection of the fluid properties of a detergent for cleaning oil contaminated soil, sand, and in general, any porous material, is another possible application

Amplified and Homozygously Deleted Genes in Glioblastoma: Impact on Gene Expression Levels

BACKGROUND: Glioblastoma multiforme (GBM) displays multiple amplicons and homozygous deletions that involve relevant pathogenic genes and other genes whose role remains unknown. METHODOLOGY: Single-nucleotide polymorphism (SNP)-arrays were used to determine the frequency of recurrent amplicons and homozygous deletions in GBM (n = 46), and to evaluate the impact of copy number alterations (CNA) on mRNA levels of the genes involved. PRINCIPAL FINDINGS: Recurrent amplicons were detected for chromosomes 7 (50%), 12 (22%), 1 (11%), 4 (9%), 11 (4%), and 17 (4%), whereas homozygous deletions involved chromosomes 9p21 (52%) and 10q (22%). Most genes that displayed a high correlation between DNA CNA and mRNA levels were coded in the amplified chromosomes. For some amplicons the impact of DNA CNA on mRNA expression was restricted to a single gene (e.g., EGFR at 7p11.2), while for others it involved multiple genes (e.g., 11 and 5 genes at 12q14.1-q15 and 4q12, respectively). Despite homozygous del(9p21) and del(10q23.31) included multiple genes, association between these DNA CNA and RNA expression was restricted to the MTAP gene. CONCLUSIONS: Overall, our results showed a high frequency of amplicons and homozygous deletions in GBM with variable impact on the expression of the genes involved, and they contributed to the identification of other potentially relevant genes

Intravenous glutamine decreases lung and distal organ injury in an experimental model of abdominal sepsis

Introduction The protective effect of glutamine, as a pharmacological agent against lung injury, has been reported in experimental sepsis; however, its efficacy at improving oxygenation and lung mechanics, attenuating diaphragm and distal organ injury has to be better elucidated. In the present study, we tested the hypothesis that a single early intravenous dose of glutamine was associated not only with the improvement of lung morpho-function, but also the reduction of the inflammatory process and epithelial cell apoptosis in kidney, liver, and intestine villi. Methods Seventy-two Wistar rats were randomly assigned into four groups. Sepsis was induced by cecal ligation and puncture surgery (CLP), while a sham operated group was used as control (C). One hour after surgery, C and CLP groups were further randomized into subgroups receiving intravenous saline (1 ml, SAL) or glutamine (0.75 g/kg, Gln). At 48 hours, animals were anesthetized, and the following parameters were measured: arterial oxygenation, pulmonary mechanics, and diaphragm, lung, kidney, liver, and small intestine villi histology. At 18 and 48 hours, Cytokine-Induced Neutrophil Chemoattractant (CINC)-1, interleukin (IL)-6 and 10 were quantified in bronchoalveolar and peritoneal lavage fluids (BALF and PLF, respectively). Results CLP induced: a) deterioration of lung mechanics and gas exchange; b) ultrastructural changes of lung parenchyma and diaphragm; and c) lung and distal organ epithelial cell apoptosis. Glutamine improved survival rate, oxygenation and lung mechanics, minimized pulmonary and diaphragmatic changes, attenuating lung and distal organ epithelial cell apoptosis. Glutamine increased IL-10 in peritoneal lavage fluid at 18 hours and bronchoalveolar lavage fluid at 48 hours, but decreased CINC-1 and IL-6 in BALF and PLF only at 18 hours. Conclusions In an experimental model of abdominal sepsis, a single intravenous dose of glutamine administered after sepsis induction may modulate the inflammatory process reducing not only the risk of lung injury, but also distal organ impairment. These results suggest that intravenous glutamine may be a potentially beneficial therapy for abdominal sepsis.Centres of Excellence Program (PRONEX-FAPERJ)Brazilian Council for Scientific and Technological Development (CNPq)Carlos Chagas FilhoRio de Janeiro State Research Supporting Foundation (FAPERJ)Sao Paulo State Research Supporting Foundation (FAPESP