Caracterizacion de nódulos tiroideos: concordancia entre estudio citopatologico y ecografia en la detección de nódulos malignos

: Los métodos imagenológicos para evaluar los nódulos tiroideos han sido motivo de estudio en las últimas décadas, especialmente la ecografía sobresale sobre las otras modalidades diagnósticas por su accesibilidad, portabilidad, y seguridad. A pesar de ello, las características ecográficas de cada nódulo han sido objeto de controversia en cuanto a su potencial detección de malignidad o benignidad. Se presenta un estudio de concordancia entre el estudio citopatológico y la ecografía para la caracterización nódulos tiroideos de naturaleza maligna y benigna, y su análisis de pruebas diagnósticas. Metodología: Se realizó un estudio descriptivo de concordancia con estudio de pruebas diagnósticas anidado. Se escogieron todos los pacientes con nódulos tiroideos a quienes se les realizó ecografía y estudio citopatológico de la lesión y se estudiaron los hallazgos ecográficos para evaluar su potencial diagnóstico para malignidad. Se incluyeron un total de 100 pacientes con nódulos tiroideos potencialmente malignos. La concordancia entre la ecografía en modo B y el estudio citopatológico fue moderada (índice kappa 0.55). La característica con mayor potencial para detectar malignidad fue la presencia de Microcalcificaciones (sensibilidad 75%, especificidad 92%).

Scar formation in the inner ear followig acoustical injury: sequence of changes from early signs of damage to healed lesion

This paper is a review of a study to investigate the effects of excessive noise exposure to the organ of Corti using chinchillas.

Using historical lesion volume data in the design of a new phase II clinical trial in acute stroke

Background and Purpose-Clinical research into the treatment of acute stroke is complicated, is costly, and has often been unsuccessful. Developments in imaging technology based on computed tomography and magnetic resonance imaging scans offer opportunities for screening experimental therapies during phase II testing so as to deliver only the most promising interventions to phase III. We discuss the design and the appropriate sample size for phase II studies in stroke based on lesion volume. Methods-Determination of the relation between analyses of lesion volumes and of neurologic outcomes is illustrated using data from placebo trial patients from the Virtual International Stroke Trials Archive. The size of an effect on lesion volume that would lead to a clinically relevant treatment effect in terms of a measure, such as modified Rankin score (mRS), is found. The sample size to detect that magnitude of effect on lesion volume is then calculated. Simulation is used to evaluate different criteria for proceeding from phase II to phase III. Results-The odds ratios for mRS correspond roughly to the square root of odds ratios for lesion volume, implying that for equivalent power specifications, sample sizes based on lesion volumes should be about one fourth of those based on mRS. Relaxation of power requirements, appropriate for phase II, lead to further sample size reductions. For example, a phase III trial comparing a novel treatment with placebo with a total sample size of 1518 patients might be motivated from a phase II trial of 126 patients comparing the same 2 treatment arms. Discussion-Definitive phase III trials in stroke should aim to demonstrate significant effects of treatment on clinical outcomes. However, more direct outcomes such as lesion volume can be useful in phase II for determining whether such phase III trials should be undertaken in the first place. (Stroke. 2009;40:1347-1352.)

Relation between neuronal morphology and electrophysiology in the Kainate lesion model of Alzheimer's Disease

This paper describes a computational and statistical study of the influence of morphological changes on the electrophysiological response of neurons from an animal model of Alzheimer's Disease (AD). We combined experimental morphological data from rat hippocampal CA1 pyramidal cells with a well-established model of active membrane properties. Dendritic morphology and the somatic response to simulated current clamp conditions were then compared for cells from the control and the AD group. The computational approach allowed us to single out the influences of neuromorphology on neuronal response by eliminating the effects of active channel variability. The results did not reveal a simple relationship between morphological changes associated with AD and changes in neural response. However, they did suggest the existence of more complex than anticipated relationships between dendritic morphology and single-cell electrophysiology.

An improved lesion detection approach based on similarity measurement between fuzzy intensity segmentation and spatial probability maps

The application of automatic segmentation methods in lesion detection is desirable. However, such methods are restricted by intensity similarities between lesioned and healthy brain tissue. Using multi-spectral magnetic resonance imaging (MRI) modalities may overcome this problem but it is not always practicable. In this article, a lesion detection approach requiring a single MRI modality is presented, which is an improved method based on a recent publication. This new method assumes that a low similarity should be found in the regions of lesions when the likeness between an intensity based fuzzy segmentation and a location based tissue probabilities is measured. The usage of a normalized similarity measurement enables the current method to fine-tune the threshold for lesion detection, thus maximizing the possibility of reaching high detection accuracy. Importantly, an extra cleaning step is included in the current approach which removes enlarged ventricles from detected lesions. The performance investigation using simulated lesions demonstrated that not only the majority of lesions were well detected but also normal tissues were identified effectively. Tests on images acquired in stroke patients further confirmed the strength of the method in lesion detection. When compared with the previous version, the current approach showed a higher sensitivity in detecting small lesions and had less false positives around the ventricle and the edge of the brain

Cognitive and bodily selves: how do they interact following brain lesion?

Dualism has long distinguished between the mental and the body experiences. Probing the structure and organisation of the self traditionally calls for a distinction between these two sides of the self coin. It is far beyond the scope of this chapter to address these philosophical issues, and our starting point will be the simple distinction between reflective processes involved in the elaboration of body image, self awareness and self-recognition (i.e. ‘the self’) and the sensori-motor dialogues involved in action control, reactions and automatisms (i.e. ‘the body’ schema). This oversimplification does not take into account the complex interactions taking place between these two levels of description, but our initial aim will be to distinguish between them, before addressing the question of their interactions. Cognitive and sensori-motor processes have frequently been distinguished (review: Rossetti and Revonsuo 2000), and it may be proposed that a similar dissociation can be put forward, a priori, between a central representation of self and a bodily representation corresponding to body schema (Figure 1).

Corticospinal tract integrity and lesion volume play different roles in chronic hemiparesis and its improvement through motor practice

Background. Initial evidence suggests that the integrity of the ipsilesional corticospinal tract (CST) after stroke is strongly related to motor function in the chronic state but not the treatment gain induced by motor rehabilitation. Objective. We examined the association of motor status and treatment benefit by testing patients with a wide range of severity of hemiparesis of the left and right upper extremity. Method. Diffusion tensor imaging was performed in 22 patients beyond 12 months after onset of stroke with severe to moderate hemiparesis. Motor function was tested before and after 2 weeks of modified constraint-induced movement therapy. Results. CST integrity, but not lesion volume, correlated with the motor ability measures of the Wolf Motor Function Test and the Motor Activity Log. No differences were found between left and right hemiparesis. Motor performance improved significantly with the treatment regime, and did so equally for patients with left and right arm paresis. However, treatment benefit was not associated with either CST integrity or lesion volume. Conclusion. CST integrity correlated best in this small trial with chronic long-term status but not treatment-induced improvements. The CST may play a different role in the mechanisms mediating long-term outcome compared to those underlying practice-induced gains after a chronic plateau in motor function.

Contextual, but not auditory, fear conditioning is disrupted by neurotoxic selective lesion of the basal nucleus of amygdala in rats

The basolateral amygdala complex (BLA) is involved in acquisition of contextual and auditory fear conditioning. However, the BLA is not a single structure but comprises a group of nuclei, including the lateral (LA), basal (BA) and accessory basal (AB) nuclei. While it is consensual that the LA is critical for auditory fear conditioning, there is controversy on the participation of the BA in fear conditioning. Hodological and neurophysiological findings suggest that each of these nuclei processes distinct information in parallel; the BA would deal with polymodal or contextual representations, and the LA would process unimodal or elemental representations. Thus, it seems plausible to hypothesize that the BA is required for contextual, but not auditory, fear conditioning. This hypothesis was evaluated in Wistar rats submitted to multiple-site ibotenate-induced damage restricted to the BA and then exposed to a concurrent contextual and auditory fear conditioning training followed by separated contextual and auditory conditioning testing. Differing from electrolytic lesion and lidocaine inactivation, this surgical approach does not disturb fibers of passage originating in other brain areas, restricting damage to the aimed nucleus. Relative to the sham-operated controls, rats with selective damage to the BA exhibited disruption of performance in the contextual, but not the auditory, component of the task. Thus, while the BA seems required for contextual fear conditioning, it is not critical for both an auditory-US association, nor for the expression of the freezing response. (C) 2009 Elsevier Inc. All rights reserved.

Avaliação morfométrica e densimétrica através de assinatura nuclear digital em biópsias de esôfago

Foram estudadas, pelo método da assinatura digital, 35 biópsias esofágicas provenientes de pacientes da província de Linxian, China, classificadas por dois observadores com ampla experiência em patologia gastrointestinal como normais, displasias ou carcinomas (8 casos normais, 6 displasias leves, 8 displasias moderadas, 4 displasias acentuadas, 4 carcinomas suspeitos de invasão e 5 carcinomas invasores). O objetivo do trabalho foi caracterizar os núcleos das populações celulares desses casos de forma que permitisse a derivação de informações diagnósticas e de possível implicação prognóstica a partir do estudo quantitativo das características nucleares de cada caso ou categoria diagnóstica. As biópsias foram coradas pelo método de Feulgen, sendo então selecionados e digitalizados 48 a 50 núcleos de cada uma delas. De cada núcleo foram extraídas 93 características cariométricas, arranjadas arbitrariamente em histograma designado como assinatura nuclear. Da média aritmética de cada característica dos núcleos de uma mesma biópsia resultou a assinatura digital do caso. A análise de funções discriminantes, baseada nas 15 características cariométricas que ofereceram melhor discriminação entre as categorias diagnósticas, mostrou que o grupo classificado como normal foi claramente distinto das demais categorias. A densidade óptica total aumentou progressivamente segundo a classificação das biópsias, do normal à displasia acentuada, sendo o valor do carcinoma semelhante ao da displasia moderada. A matriz de comprimento de seqüência apresentou o mesmo perfil, ou seja, ambas as características ofereceram discriminação clara entre as categorias diagnósticas, com exceção do carcinoma invasor, cujos valores foram superponíveis aos da displasia moderada. O estudo demonstrou a viabilidade da quantificação de características nucleares através das assinaturas nucleares digitais, que demonstraram diferenças estatisticamente significativas entre diferentes categorias diagnósticas e a elevação progressiva dos valores mensurados relacionados com o espectro das lesões, apresentando-as como um histograma (assinatura digital nuclear).

Nematicidal activity of Solanum nigrum and S. sisymbriifolium extracts against the root-lesion nematode Pratylenchus goodeyi and its effects on infection and gene expression

The control of Pratylenchus goodeyi a common nematode parasite of banana crop in Madeira Island can benefit from searching for natural nematicides through plants extracts. With this aim we submitted Solanum nigrum and S. sisymbriifolium dried plants to a sequential extraction in the solvent sequence of dichloromethane, acetone, ethanol and water, and to na aqueous extraction of the fresh and dried plants. Analyses with the extracts at several concentrations were used to assess mobility and mortality on P. goodeyi. Results showed that the water extract and aqueous extracts from both plants at a concentration of 10 mg/mL affected nematode mobility and caused mortality but the acetone extract from S. nigrum was the most efficient, causing 100% mortality whereas dichloromethane had no effect on P. goodeyi. Determination of the lipophilic and phenolic compounds present in the two most effective Solanum extracts (acetone and water) and in dichloromethane extract revealed that some of these compounds had nematicidal activity. S. nigrum acetone extract (10 mg/mL) was used to find out the nematicidal potential following the effect at gene expression level and nematode behaviour. Genes coding for calreticulin and beta-1,4- endoglucanase related to parasitism and translocon-associated protein putatively connected to stress were obtained and its relative expression assessed in nematodes exposed to the extract. Results revealed that expression of Pg-CRT decreased showing to influence the infection, Pg-ENG remained steady and Pg-TRAPδ was induced over time exposure. Biological assays showed that P. goodeyi mobility and ability to infect the banana roots were affected as a decrease in the number of nematodes that reached the roots was obtained with the increased exposure time to the extract being implicated in the infection success. The information obtained from this thesis showed that S. nigrum has potential to be used for the development of a new control strategy against plant-parasitic nematodes.

Muscle lesion treatment in Brazilian soccer players: Theory vs. Practice

Background: In this study we evaluated the rehabilitation profile of Brazilian soccer players which underwent lower limb muscle lesions.Methods: This is a descriptive investigation. We evaluated 139 professional soccer players (1724 years old). We evaluated the following variables: muscle lesion diagnosis, symptoms, non steroidal anti-inflammatory used, physiotherapy treatment, which physiotherapy recourses was used if treated and train adaptation.Results: In great part of the athletes muscle lesion remained between 2 weeks and 1 month. Around 54% were diagnosed by a physician; the other part was diagnosed by a physical therapist. Non steroidal anti-inflammatory were prescribed by physicians in 42% of the cases; in 7% the physical therapist prescribed the medication while in 49% of the cases the masseur prescribed the drug. More than 1/4 of the athletes received physiotherapy treatement between 48 hours and 5 days. Isometric exercise therapy was applied in 15% of the cases. 63% were not accompanied by the physiotherapist on their return to the field. 48% received massages immediately after injury.Conclusion: We presented discrepancy between the recommended theory described by several researches and the practice. We indicate the necessity of recycling in a general context the rehabilitation of muscle injuries.

Histological evaluation of the lesion induced by inoculation of Leishmania mexicana in the cheek pouch of the hamster

No presente estudo, investigamos o papel da resposta imune na morfologia do granuloma leishmaniótico induzido na bolsa jugal do hamster, um local imunologicamente privilegiado, após inoculação de 3x10(5) Leishmania mexicana. Os animais foram avaliados histológica e imunologicamente até os 120 dias da inoculação. Independente da época do sacrifício, os animais foram sempre não reatores ao teste do coxim plantar. Histologicamente, a inoculação de Leishmania mexicana na bolsa jugal resultou na formação de abcesso que evoluiu para reação granulomatosa rica em formas amastigotas e, posteriormente, para resolução. Esses resultados sugerem que o desenvolvimento da resposta imune não é preponderante no controle da infecção induzida pela Leishmania mexicana inoculada subcutaneamente na bolsa jugal do hamster. Sugerem ainda que os macrófagos que compõe os granulomas leishmanióticos são capazes de eliminar esse parasita, independente da presença de resposta imune avaliável pelo teste do coxim plantar.