Patho-morphological study of the supplemental groove

The following results have been obtained in consequence of patho-morphological examination regarding the supplemental groove.1. Light microscopic observation of cross-sectioned supplemental grooves revealed that most of them were shallow in the form of plate or bowl. Some of the supplemental grooves had contents not described in the past and the structure of the contents was not clear under a light microscope. The contents were found in 22% of the supplemental grooves examined.2. The contents in supplemental grooves which were confirmed under a light microscope were found to consist of enamel itself when examined by means of an electron microscope. Microhardness measurements of this enamel showed less than one third the values of normal enamel. By means of microradiography, it was established that radiolucency of this enamel was, for the most part, much higher than normal enamel.3. It was ascertained that enamel with low hardness and high radiolucency constitutes the contents of supplemental grooves. Judging from its tissue properties, the contents were believed to be susceptible to attack by caries. This view was supported by the results of an investigation of caries sites in supplemental grooves.L’examen morpho-pathologique de sillons surnuméraires a donné les résultats suivants:1. En coupes transversales observées en microscopie classique, les sillons surnuméraires apparaissent peu profonds, en forme d’assiette ou de coupe. Dans certains, on trouve un contenu, non encore décrit dans la littérature et dont la structure n’apparaît pas nettement en microscopie classique. On trouve ce contenu dans 22% des sillons surnuméraires étudiés.2. Etudié en microscopie électronique à transmission, le contenu des sillons surnuméraires apparaît fait d’émail. Les mesures de dureté indiquent pour cet émail des valeurs inférieures d’un tiers à celles de l’émail normal. La microradiographie montre que cet émail est, en général, beaucoup moins radiodense que l’émail normal.3. Etant donné que le contenu des sillons surnuméraires s’est révélé être un émail de faible dureté et de faible radiodensité, on peut considérer que, par ses propriétés tissulaires, cet émail est sensible à l’attaque carieuse. Cette hypothèse est corroborée par les résultats de l’étude des sites carieux dans les sillons surnuméraires

The diagnostic accuracy of US, CT, MRI and 1H-MRS for the evaluation of hepatic steatosis compared with liver biopsy: a meta-analysis

OBJECTIVE: To meta-analyse the diagnostic accuracy of US, CT, MRI and (1)H-MRS for the evaluation of hepatic steatosis. METHODS: From a comprehensive literature search in MEDLINE, EMBASE, CINAHL and Cochrane (up to November 2009), articles were selected that investigated the diagnostic performance imaging techniques for evaluating hepatic steatosis with histopathology as the reference standard. Cut-off values for the presence of steatosis on liver biopsy were subdivided into four groups: (1) >0, >2 and >5% steatosis; (2) >10, >15 and >20%; (3) >25, >30 and >33%; (4) >50, >60 and >66%. Per group, summary estimates for sensitivity and specificity were calculated. The natural-logarithm of the diagnostic odds ratio (lnDOR) was used as a single indicator of test performance. RESULTS: 46 articles were included. Mean sensitivity estimates for subgroups were 73.3-90.5% (US), 46.1-72.0% (CT), 82.0-97.4% (MRI) and 72.7-88.5% ((1)H-MRS). Mean specificity ranges were 69.6-85.2% (US), 88.1-94.6% (CT), 76.1-95.3% (MRI) and 92.0-95.7% ((1)H-MRS). Overall performance (lnDOR) of MRI and (1)H-MRS was better than that for US and CT for all subgroups, with significant differences in groups 1 and 2. CONCLUSION: MRI and (1)H-MRS can be considered techniques of choice for accurate evaluation of hepatic steatosi

Interaction between valence of empathy and familiarity: is it difficult to empathize with the positive events of a stranger?

Background: Empathy in humans is thought to have evolved via social interactions caused by the formation of social groups. Considering the role of empathy within a social group, there might be a difference between emotional empathy for strangers and familiar others belonging to the same social group. In this study, we used the global field power (GFP) index to investigate empathic brain activity during observation of a cue indicating either a negative or positive image viewed by a stranger or close friend. Methods: Sixteen healthy participants observed a partner performing an emotional gambling task displayed on a monitor. After the partner\u27s choice-response, a frowning or smiling face symbol was simultaneously presented to the participant\u27s monitor while a negative or positive emotional image was presented to the partner\u27s monitor. All participants observed a control condition (CT) showing a computer trial, a stranger-observation condition (SO) showing the trial of a stranger, and a friend-observation condition (FO) to observe the trial of a close friend. During these observations, participants\u27 event-related potentials (ERPs) were recorded to calculate GFP, and after the task, a subjective assessment of their feelings was measured. Results: Positive emotion was significantly larger under the FO compared to the CT and the SO. Significantly larger negative emotion was found under the SO and FO compared to the CT. In response to a positive cue, significantly larger GFP during 300 to 600 ms was observed under the FO compared to the CT and SO. In response to a negative cue, significantly larger GFP was observed under the FO and SO compared to the CT. A significantly larger GFP under the SO was found in response to only a negative cue. Topographic map analysis suggested that these differences were related to frontal-occipital dynamics. GFP was significantly correlated with empathic trait. Conclusion: These results revealed that familiarity with another person has different effects depending on the valence of empathy. Negative empathy, including the danger perception function, might easily occur even among strangers, whereas positive empathy related to nursing and supporting an inner group does not happen easily with strangers