High-Resolution Magnetic Resonance Imaging Can Reliably Detect Orbital Tumor Recurrence after Enucleation in Children with Retinoblastoma.

PURPOSE: Orbital tumor recurrence is a rare but serious complication in children with retinoblastoma, leading to a high risk of metastasis and death. Therefore, we assume that these recurrences have to be detected and treated as early as possible. Preliminary studies used magnetic resonance imaging (MRI) to evaluate postsurgical findings in the orbit. In this study, we assessed the diagnostic accuracy of high-resolution MRI to detect orbital tumor recurrence in children with retinoblastoma in a large study cohort. DESIGN: Consecutive retrospective study (2007-2013) assessing MRI findings after enucleation. PARTICIPANTS: A total of 103 MRI examinations of 55 orbits (50 children, 27 male/23 female, mean age 16.3±12.4 months) with a median time of 8 months (range, 0-93) after enucleation for retinoblastoma. METHODS: High-resolution MRI using orbital surface coils was performed on 1.5 Tesla MRI systems to assess abnormal orbital findings. MAIN OUTCOME MEASURES: Five European experts in retinoblastoma imaging evaluated the MRI examinations regarding the presence of abnormal orbital gadolinium enhancement and judged them as "definitive tumor," "suspicious of tumor," "postsurgical condition/scar formation," or "without pathologic findings." The findings were correlated to histopathology (if available), MRI, and clinical follow-up. RESULTS: Abnormal orbital enhancement was a common finding after enucleation (100% in the first 3 months after enucleation, 64.3% >3 years after enucleation). All histopathologically confirmed tumor recurrences (3 of 55 orbits, 5.5%) were correctly judged as "definitive tumor" in MRI. Two orbits from 2 children rated as "suspicious of tumor" received intravenous chemotherapy without histopathologic confirmation; further follow-up (67 and 47 months) revealed no sign of tumor recurrence. In 90.2%, no tumor was suspected on MRI, which was clinically confirmed during follow-up (median follow-up after enucleation, 45 months; range, 8-126). CONCLUSIONS: High-resolution MRI with orbital surface coils may reliably distinguish between common postsurgical contrast enhancement and orbital tumor recurrence, and therefore may be a useful tool to evaluate orbital tumor recurrence after enucleation in children with retinoblastoma. We recommend high-resolution MRI as a potential screening tool for the orbit in children with retinoblastoma to exclude tumor recurrence, especially in high-risk patients within the critical first 2 years after enucleation.

Lateral periodontal cysts: a retrospective study of 11 cases

Objective: To describe the clinical, radiological and histopathological features of lateral periodontal cysts among patients diagnosed in different centers (Vall d"Hebron General Hospital, Granollers General Hospital, the Teknon Medical Center, and the Master of Oral Surgery and Implantology of the University of Barcelona Dental School; Barcelona, Spain). Study design: A retrospective observational study was made of 11 lateral periodontal cysts, all of which were diagnosed following a thorough clinical examination, radiological study and posterior histological study. Results: The mean patient age was 37 years, and males predominated over females. The mean lesion size was 1.25 cm. A single relapse was recorded 7 years after removal of the initial lesion. All the cysts were surgically removed. Discussion and conclusions: Lateral periodontal cysts are very infrequent, and are characterized by the preserved vitality of the adjacent teeth. Identification of the lesion is initially based on the clinical findings, though histological study is required to confirm the diagnosis. The treatment of choice is the surgical removal, though occasional relapses have been documented

Validação lateral em relações quantitativas entre estrutura e atividade farmacológica, QSAR

The comparative QSAR is a tool for validating any statistical model that seems to be reasonable in describing an interaction between a bioactive new chemical entity, BIONCE, and the biological system. In order to deeper the understanding of the relationships and the meaning of parameters within the model it is necessary some kind of lateral validation. This validation can be accomplished by chemical procedures using physicochemical organic reactions and by means of biological systems. In this paper we review some of such comparisons and also present a lateral validation between the same set of antimicrobial hydrazides acting against Saccharomyces cerevisiae yeast and Escherichia coli bacterium cells. QSARs are presented to shed light in this important way of stating that the QSAR model is not the endpoint, but the beginning.

The stability of right- and left-handed alpha-helices as a function of monomer chirality

Poly-L-alanine forms stable right-handed alpha-helices, whereas Poly-D-alanine is stable as left-handed alpha helices.

Brain Dopamine and Serotonin Receptors in the Perception of Pain. Positron Emission Tomography Studies in Healthy Subjects

The role of dopamine and serotonin in spinal pain regulation is well established. However, little is known concerning the role of brain dopamine and serotonin in the perception of pain in humans. The aim of this study was to assess the potential role of brain dopamine and serotonin in determining experimental pain sensitivity in humans using positron emission tomography (PET) and psychophysical methods. A total of 39 healthy subjects participated in the study, and PET imaging was performed to assess brain dopamine D2/D3 and serotonin 5-HT_1A receptor availability. In a separate session, sensitivity to pain and touch was assessed with traditional psychophysical methods, allowing the evaluation of potential associations between D2/D3 and 5-HT_1A binding and psychophysical responses. The subjects’ responses were also analyzed according to Signal Detection Theory, which enables separate assessment of the subject’s discriminative capacity (sensory factor) and response criterion (non-sensory factor). The study found that the D2/D3 receptor binding in the right putamen was inversely correlated with pain threshold and response criterion. 5-HT_1A binding in cingulate cortex, inferior temporal gyrus and medial prefrontal cortex was inversely correlated with discriminative capacity for touch. Additionally, the response criterion for pain and intensity rating of suprathreshold pain were inversely correlated with 5-HT_1A binding in multiple brain areas. The results suggest that brain D2/D3 receptors and 5-HT_1A receptors modulate sensitivity to pain and that the pain modulatory effects may, at least partly, be attributed to influences on the response criterion. 5-HT_1A receptors are also involved in the regulation of touch by having an effect on discriminative capacity.

Studying Memory Encoding to Promote Reliable Engagement of the Medial Temporal Lobe at the Single-subject Level

The medial temporal lobe (MTL)-comprising hippocampus and the surrounding neocortical regions-is a targeted brain area sensitive to several neurological diseases. Although functional magnetic resonance imaging (fMRI) has been widely used to assess brain functional abnormalities, detecting MTL activation has been technically challenging. The aim of our study was to provide an fMRI paradigm that reliably activates MTL regions at the individual level, thus providing a useful tool for future research in clinical memory-related studies. Twenty young healthy adults underwent an event-related fMRI study consisting of three encoding conditions: word-pairs, face-name associations and complex visual scenes. A region-of-interest analysis at the individual level comparing novel and repeated stimuli independently for each task was performed. The results of this analysis yielded activations in the hippocampal and parahippocampal regions in most of the participants. Specifically, 95% and 100% of participants showed significant activations in the left hippocampus during the face-name encoding and in the right parahippocampus, respectively, during scene encoding. Additionally, a whole brain analysis, also comparing novel versus repeated stimuli at the group level, showed mainly left frontal activation during the word task. In this group analysis, the face-name association engaged the HP and fusiform gyri bilaterally, along with the left inferior frontal gyrus, and the complex visual scenes activated mainly the parahippocampus and hippocampus bilaterally. In sum, our task design represents a rapid and reliable manner to study and explore MTL activity at the individual level, thus providing a useful tool for future research in clinical memory-related fMRI studies.

A brief introduction to molecular orbital theory of simple polyatomic molecules for undergraduate chemistry students

A simple, four-step method for better introducing undergraduate students to the fundamentals of molecular orbital (MO) theory of the polyatomic molecules H2O, NH3, BH3 and SiH4 using group theory is reported. These molecules serve to illustrate the concept of ligand group orbitals (LGOs) and subsequent construction of MO energy diagrams on the basis of molecular symmetry requirements.

Síntese e caracterização de copolímeros de cadeia lateral derivados de acrilatos de 4,5-di-hidroisoxazol e do (-)-mentol

Five monomers 5-[4-(5-cyano-4,5-dihydroisoxazol-3-yl)phenoxy]undecyl acrylate (7a); n-alkyl 3-{4-[5-(acryloyloxyundecyl)oxyphenyl]}-4,5-dihydroisoxazole-5-carboxylate (7b,c for n-butyl and n-hexyl, respectively); 3-{4-[5-(acryloyloxyundecyl) oxyphenyl]}-4,5-dihydroisoxazole-5-carboxylic acid (7d) and (1R,2S,5R)-2-isopropyl-5-methylcyclohexyl acrylate (9) and the corresponding copolymers 10a-d,11 and homopolymers 12 from 7a and 13 from 9 were designed and synthesized. Except for acrylate 9 which is derived from (-)-menthol, all of the monomers belong to the series containing the isoxazoline ring linked to the acrylate unit by a flexible spacer chain of eleven methylene units. They presented low glass temperature and despite birefringence behavior, these copolymers showed no mesomorphic properties.

Advanced orbital pipe welding

Since the introduction of automatic orbital welding in pipeline application in 1961, significant improvements have been obtained in orbital pipe welding systems. Requirement of more productive welding systems for pipeline application forces manufacturers to innovate new advanced systems and welding processes for orbital welding method. Various methods have been used to make welding process adaptive, such as visual sensing, passive visual sensing, real-time intelligent control, scan welding technique, multi laser vision sensor, thermal scanning, adaptive image processing, neural network model, machine vision, and optical sensing. Numerous studies are reviewed and discussed in this Master’s thesis and based on a wide range of experiments which already have been accomplished by different researches the vision sensor are reported to be the best choice for adaptive orbital pipe welding system. Also, in this study the most welding processes as well as the most pipe variations welded by orbital welding systems mainly for oil and gas pipeline applications are explained. The welding results show that Gas Metal Arc Welding (GMAW) and its variants like Surface Tension Transfer (STT) and modified short circuit are the most preferred processes in the welding of root pass and can be replaced to the Gas Tungsten Arc Welding (GTAW) in many applications. Furthermore, dual-tandem gas metal arc welding technique is currently considered the most efficient method in the welding of fill pass. Orbital GTAW process mostly is applied for applications ranging from single run welding of thin walled stainless tubes to multi run welding of thick walled pipes. Flux cored arc welding process is faster process with higher deposition rate and recently this process is getting more popular in pipe welding applications. Also, combination of gas metal arc welding and Nd:YAG laser has shown acceptable results in girth welding of land pipelines for oil and gas industry. This Master’s thesis can be implemented as a guideline in welding of pipes and tubes to achieve higher quality and efficiency. Also, this research can be used as a base material for future investigations to supplement present finding.

Efeito da inundação lateral sobre a distribuição da vegetação ripária em um trecho do rio Cuiabá, MT

Estudos hidrológicos e fitossociológicos foram realizados num perfil topográfico de 550 m instalado perpendicularmente ao rio Cuiabá, no Município de Rosário Oeste, MT, para analisar a influência da inundação sobre a distribuição da vegetação ripária. Utilizando os dados fluviométricos da estação de Rosário Oeste de 1966 a 2003, um modelo hidrológico de remanso em regime subcrítico foi ajustado, permitindo estabelecer a série hidrológica na área de estudo. A partir dessa série, os intervalos de recorrência nessa área foram obtidos. Os resultados sugeriram que a margem do canal principal, o canal secundário e o dique marginal, a planície de inundação e o terraço alagam a cada ~1 1,7 ano, ~1,77 2,8 anos, ~3 anos e de ~3,25 a ~39 anos, respectivamente. A espécie Combretum leprosum Mart. (Combretaceae) apresentou maior VI na margem do canal principal, Callisthene fasciculata (Spr.) Mart. (Vochysiaceae) na margem do canal principal e no terraço e Licania parvifolia Huber (Chrysobalanaceae), Cariniana estrellensis (Raddi) Kuntze. (Lecythidaceae) e Vochysia divergens Pohl. (Vochysiaceae) na planície de inundação. Os resultados indicaram que a frequência e, principalmente, o tempo de alagamento são os principais determinantes ecológicos da distribuição das espécies vegetais ao longo do perfil topográfico.

Detection of soybean planted areas through orbital images based on culture spectral dynamics

The soybean is important to the economy of Brazil, so the estimation of the planted area and the production with higher antecedence and reliability becomes essential. Techniques related to Remote Sensing may help to obtain this information at lower cost and less subjectivity in relation to traditional surveys. The aim of this study is to estimate the planted area with soybean culture in the crop of 2008/2009 in cities in the west of the state of Paraná, in Brazil, based on the spectral dynamics of the culture and through the use of the specific system of analysis for images of Landsat 5/TM satellite. The obtained results were satisfactory, because the classification supervised by Maximum Verisimilitude - MaxVer along with the techniques of the specific system of analysis for satellite images has allowed an estimate of soybean planted area (soybean mask), obtaining values ​​of the metrics of Global Accuracy with an average of 79.05% and Kappa Index over 63.50% in all cities. The monitoring of a reference area was of great importance for determining the vegetative phase in which the culture is more different from the other targets, facilitating the choice of training samples (ROIs) and avoiding misclassifications.

Uso de imagens do sensor orbital modis na estimação de datas do ciclo de desenvolvimento da cultura da soja para o estado do Paraná – Brasil

RESUMO O Estado do Paraná caracteriza-se por uma grande variabilidade de épocas de semeadura (DS) e, consequentemente, pelo desenvolvimento máximo vegetativo (DMDV), colheita (DC) e ciclo (CI) para a cultura da soja. O objetivo deste trabalho foi estimar essas datas para o período de primavera-verão do ano-safra de 2011/2012, por meio de séries temporais de imagens do Índice de Vegetação Realçado (do inglês Enhanced Vegetation Index - EVI) do sensor Modis (Moderate Resolution Imaging Spectroradiometer). Gerou-se um perfil espectrotemporal médio de EVI, considerando todos os pixels mapeados como soja dentro de cada município. Estes dados serviram de entrada no software Timesat para estimar os decêndios do ciclo da cultura (DS, DMDV, DC e CI) por municípios. Os resultados mostraram que existe grande variabilidade de datas de plantio em diferentes mesorregiões do Estado. Verificaram-se também divergências entre os resultados encontrados e os dados oficiais de DS e DC. A maior parte da semeadura (65,16%) esteve entre o terceiro decêndio de outubro e o primeiro decêndio de novembro. A maior parte da área de soja do Estado do Paraná (65,46%) teve seu DMDV em janeiro e colheita em março (53,92%).

Tratamento cirúrgico da ginecomastia com pedículos lateral e medial

Ginecomastia é o aumento da mama masculina que pode acometer até 65% dos indivíduos deste sexo na fase infanto-puberal, compreendida entre 13 e 16 anos. Tem como principais causas hepatite ou cirrose hepática, carcinoma ou doenças inflamatórias pulmonares crônicas, carcinomas ou disfunções testiculares, tumores glandulares (pituitária, supra-renal), alterações dos níveis séricos de testosterona, síndromes genéticas (síndrome de Klinefelter, p.ex.), uso de drogas como heroína, maconha ou anabolizantes e hanseníase. Podemos classificar a ginecomastia quanto ao volume, quanto aos tecidos que a compõem (gordurosa ou pseudoginecomastia, glandular e mista), ou quanto ao tratamento necessário para sua correção cirúrgica (pequena, moderada e grave). O tratamento das formas mais graves de ginecomastia é muito diferente daquele aplicado às formas mais suaves, pois nas formas graves, além da ressecção dos tecidos gorduroso e glandular, existe a necessidade de ressecção da pele em excesso e o reposicionamento do complexo aréolo-mamilar. O objetivo deste trabalho é descrever uma técnica cirúrgica específica para estes pacientes portadores de formas graves de ginecomastia, através de dois pedículos dermogordurosos, um lateral e um medial, com aproximadamente 2cm de espessura, mantendo assim a nutrição do complexo aréolo-mamilar. Esses pedículos são delimitados entre as bissetrizes dos quadrantes súpero-lateral e ínfero-lateral, e súpero-medial e ínfero-medial, tendo o mamilo como vértice. Na área de pele excessiva periareolar, obtida através do pinçamento interdigital, é realizada a desepidermização dos pedículos lateral e medial e ressecção de toda pele e tecido celular subcutâneo até a fáscia peitoral nas regiões superior e inferior aos pedículos; a síntese é realizada em dois planos, sendo periareolar a cicatriz resultante. Foram operados com esta técnica vinte pacientes com forma grave de ginecomastia, com média etária de 23,3 anos; sendo seis pacientes da raça negra. O bom posicionamento do complexo aréolo-mamilar e uma cicatriz periareolar resultante, bem como a retirada de conteúdo suficiente, foram as principais vantagens observadas. Como complicações, tivemos assimetria das placas aréolo-mamilares em dois casos, nos quais havia acentuada diferença entre os dois lados na avaliação pré-operatória; cicatrização hipertrófica em um paciente da raça negra, cuja cicatriz foi atenuada com injeções intracicatriciais de triancinolona; necrose parcial de aréola em um caso, cuja ferida cicatrizou por segunda intenção, dispensando qualquer tratamento local posterior; deiscência de sutura periareolar em um caso, no qual foi feita a ressutura, com bom resultado, e quatro pacientes apresentaram coleção sero-hemática subcutânea, que foram drenadas e não apresentaram recidiva.

Tratamento cirúrgico do megacólon chagásico: retocolectomia abdominal com anastomose colorretal mecânica término-lateral

Trinta e cinco doentes portadores de megacólon chagásico foram operados pela técnica da retocolectomia abdominal com anastomose colorretal mecânica término-lateral durante o período de 1993 a 1997. Vinte (57,14%) doentes eram do sexo feminino e 15 (42,85%) do masculino. A idade variou de 27 a 76 anos, com média de 51 anos. A operação constou de ressecção do segmento dilatado, sepultamento do coto retal na altura da reflexão peritoneal com grampeador, dissecção do espaço retrorretal até o plano dos músculos elevadores e anastomose colorretal mecânica término-lateral posterior. Em quatro (11,42%) doentes a anastomose foi anterior. Em três (8,57%) doentes, o teste de escape da anastomose foi positivo, o que obrigou a complementação manual da sutura em dois (5,71 %) e sutura e ostomia derivativa em um (2,85%). Ocorreram sete (20,00%) complicações pós-operatórias precoces, sendo quatro consideradas relevantes (11,42%) e quatro (11,42%) complicações tardias. Houve um (2,85%) óbito por complicação clínica. Os doentes submetidos a colostomia foram reoperados para fechamento da mesma sem intercorrências. A totalidade dos doentes apresenta hábito intestinal normal. Não houve referências a alterações gênito-urinárias, nem a incontinência fecal. A anastomose foi tocada ou visibilizada em todos os pacientes examinados, durante o seguimento ambulatorial. Não houve casos de fecaloma no coto retal. Embora os resultados iniciais sejam bastante satisfatórios, é necessário maior tempo de observação para se avaliar a possibilidade de recidiva.