Telementoring for minimally invasive surgical training by wireless robot.

Hands-on training courses with local mentoring are excellent educational tools in laparoscopic surgery; however, the need for the physical presence of specialized instructors represents a limitation because of costs, time, and geographic constraints. Remote robotic telementoring using a wireless videoconferencing mobile robot could represent an alternative to local instruction. The authors compare local active and passive mentoring with remote robotic telementoring using the wireless RP-6 Robot that worked through a WiFi 802.11b connection during a hands-on laparoscopic training session. Surgeons were mentored once in France from the United States. Robot mentoring was well received and appreciated (assessment score of 2.65; scale, 0 to 4). There was no statistical difference in the different mentoring sessions (active, passive, and remote). Mobile wireless robot is a valuable tool in laparoscopic telementoring. Robotic-assisted telementoring may not replace onsite mentoring, but it may enhance educational opportunities and the quality of hands-on training courses by implementing tutoring with expert assistance from remote locations.

Long-term liver histology improvement in patients with chronic hepatitis C and sustained response to interferon.

A retrospective multicentre survey was conducted to evaluate, in patients with chronic hepatitis C, the long-term liver histological changes induced by interferon (IFN). A total of 112 patients (mean age 46.4 years) were studied. All patients had received a 6-12-month IFN-alpha course (6-18 MU/week) and had successively undergone clinical, biochemical and virological follow-up for at least 36 months (range: 36-76). In each patient, two liver biopsies had been performed: 1-6 months before treatment and, 12-76 months after its completion. In 87 patients with biochemical and virological sustained response persisting for 12 months after therapy, post-treatment liver necroinflammation and fibrosis mean(+/-SD) scores (Knodell index) were significantly lower than pretreatment scores (2.9 +/- 2.2 vs 6.8 +/- 2.9 and 0.8 +/- 1.0 vs 1.2 +/- 1.1, respectively; P < 0.01). In 25 patients who relapsed within 1 year, necroinflammation and fibrosis post-treatment mean scores were similar to pretreatment scores (7.4 +/- 3.2 vs 6.9 +/- 3.1 and 1.8 +/- 1.3 vs 1.6 +/- 1.2, respectively; P > 0.05). On an individual basis, necroinflammation decreased in 87% of sustained responders but only in 36% of relapsers (P < 0.001), whereas fibrosis decreased in 44% of sustained responders but only in 14% of relapsers (P < 0.001). In sustained responders with biopsies performed 12-23 months (n=34), 24-35 months (n=26) or more than 36 months (n=27) after treatment, a progressive decrease of mean necroinflammatory score was observed (-2.6 +/- 2.1, -4.1 +/- 3.4 and -5.2 +/- 3.7 points, respectively; P < 0.01). A similar pattern was observed in fibrosis score (-0.3 +/- 0.6, -0.3 +/- 0.7 and -0.7 +/- 0.9 points, respectively; P < 0.05). Hence, among chronic hepatitis C patients treated with IFN, those with a 12-month sustained response, unlike those who relapse, have a long-term progressive reduction and, in some cases, a complete regression of liver histological damage.

Doppler sonography measurement of portal blood flow velocity after glucagon injection in patients with chronic HCV infection.

Doppler sonography measurement of portal flow velocity (PFV) after glucagon injection was performed in 45 patients with chronic hepatitis C virus (HCV) infection. Patients were divided into three groups: group 1 = no or mild liver fibrosis; group 2 = moderate to severe liver fibrosis, and group 3 = liver cirrhosis. All patients were examined using a Doppler ultrasound (US) multipurpose equipment and a convex 3.5-MHz probe, 10 min before (baseline), as well as 5 and 10 min after, IV administration of 1 mg of glucagon chloride. No significant differences were found in mean baseline PFV among group 1 (19.4 +/- 2.4 cm/s), group 2 (20.1 +/- 3.6 cm/s) and group 3 (17.5 +/- 3.7 cm/s). Five minutes after glucagon injection, all three groups showed significantly increased values of mean PFV (25.6 +/- 4.8, 23.7 +/- 4.0 and 19.5 +/- 5.0 cm/s, respectively; p < 0.05 vs. baseline). The mean increase of PFV above baseline was significantly higher in group 1 (7.9 +/- 3.7 cm/s) than in group 2 (4.5 +/- 3.9 cm/s) (p < 0.05) or in group 3 (2.7 +/- 2.3 cm/s) (p < 0.05). A significant inverse correlation was found between individual values of fibrosis score and of individual increase of PFV. In patients with chronic HCV infection, Doppler sonography measurement of PFV after glucagon injection could be useful in assessing the severity of liver histological damage.

Spelling-sound regularity effects on eye fixations in reading.

An interaction of word frequency and word regularity has typically been observed in naming and lexical decision experiments in which, in addition to an overall effect of word frequency, responses to low-frequency exception words are slower than those to low-frequency regular words, while no such difference occurs with high-frequency words. The only eye movement study to examine this effect in reading (Inhoff & Topolski, 1994) reported only transient effects of regularity. In the present experiment, we examined the frequency x regularity interaction using different stimuli than those of Inhoff and Topolski and also varied the parafoveal preview of the target word prior to fixation. When the preview was valid, the frequency x regularity interaction appeared. However, with an invalid preview, the effect of regularity disappeared. The results suggest that the activation of phonological codes is a very early component of reading.

Neuroanatomy, circuitry and plasticity of word reading.

The use of neuroimaging has provided a basis for suggesting the brain areas active during reading of words and sentences. When combined with high density electrical recording from the scalp, it is possible to obtain information on the time course of activation of these brain areas and compare them with the temporal structure of reading from studies of eye movements. The paper summarizes results in these areas and suggests how acquisition and practice of the skill might alter the circuitry involved.

Establishing a time-line of word recognition: evidence from eye movements and event-related potentials.

The average duration of eye fixations in reading places constraints on the time for lexical processing. Data from event related potential (ERP) studies of word recognition can illuminate stages of processing within a single fixation on a word. In the present study, high and low frequency regular and exception words were used as targets in an eye movement reading experiment and a high-density electrode ERP lexical decision experiment. Effects of lexicality (words vs pseudowords vs consonant strings), word frequency (high vs low frequency) and word regularity (regular vs exception spelling-sound correspondence) were examined. Results suggest a very early time-course for these aspects of lexical processing within the context of a single eye fixation.

[Glucagon test for Doppler sonography measurement of portal flow in chronic HCV infections] / Il test al glucagone nello studio eco-Doppler del flusso portale nell'infezione cronica da HCV.

Purpose - To evaluate whether Doppler sonography measurement of portal flow velocity (PFV) after glucagon injection can be useful in assessing the severity of liver damage in chronic HCV infection. Methods - Forty-five patients (32 males and 13 females; mean age 54.1 14.8 years) with biochemical (raised serum ALT levels), virological (positive serum HCV RNA test) and histological (liver biopsy) evidence of chronic HCV infection were included in the study. According to hepatitis staging (degree of liver fibrosis), as assessed by Knodell histological activity index, patients were divided into three groups: group 1 (n.=17), with no or mild fibrosis (fibrosis score: 0-1); group 2 (n.=11), with severe fibrosis (score: 3); and group 3 (n.=17), with liver cirrhosis (score: 4). For sonographic measurements of PFV, a Doppler ultrasound multi-purpose equipment and a convex 3.5 MHz probe were used. All patients were examined after an 8-hour fast, in supine position, 10 min before (baseline), as well as 5 and 10 min after, intravenous administration of 1 mg of glucagon chloride (Novo Nordisk). Statistical analysis was performed by ANOVA test, Bonferroni t test and Spearman rank correlation test. Results - No significant differences were found in mean basal PFV of group 1 (19.4 2.4 cm/sec), group 2 (20.1 3.6 cm/sec) and group 3 (17.5 3.7 cm/sec) (p > 0.05). Five minutes after glucagon injection, all the three groups showed a significant increase in PFV (25.6 4.8,23.7 4.0 and 19.5 5.0 cm/sec, respectively; p < 0.05 vs baseline). The peak increase in PFV after glucagon injection was significantly higher in group 1 (7.9 3.7 cm/sec; 40.7% of basal value) than in group 2 (4.5 3.9 cm/sec; 22.4%) (p < 0.05) and in group 3 (2.7+2.3 cm/sec; 15.4%) (p < 0.05). A significant (p< 0.001) inverse correlation was also found between the patients fibrosis scores and peak increments of PFV induced by glucagon. Conclusions - In some patients with chronic HCV infection, Doppler sonography measurement of PFV after glucagon injection can be useful, in combination with other non invasive ultrasound investigations, both in staging of liver disease and in monitoring the progression of liver histological damage.

Eye movement control in reading: a comparison of two types of models.

Two classes of models have been proposed to account for eye movement control during reading. Proponents of the 1st class of model claim that the decision of when to move the eyes (reflected in fixation duration) is primarily influenced by the status of on-line language processing such as lexical access. Supporters of the 2nd class of model, however, maintain that (a) lower level oculomotor factors such as fixation location govern the decision of when to move the eyes and (b) lexical variables exert only a weak influence. In this study, fixation duration on low-and high-frequency target words was examined as a function of fixation location and the number of fixations on a target word. The data are inconsistent with an oculomotor model.

Resolution of lexical ambiguity: evidence from an eye movement priming paradigm.

Subjects' eye movements were monitored while they read 2-sentence passages of text. A target-word region was defined in the 2nd sentence of each passage. During the initial 35 ms of a target region eye fixation, an ambiguous word was presented as a prime. A target word subsequently replaced the prime during the fixation. Priming was measured by comparing fixation times on targets preceded by semantically related versus unrelated ambiguous primes. The type of prior context (consistent vs. inconsistent), type of ambiguous prime (biased vs. balanced), and strength of instantiated meaning (dominant vs. subordinate) could all affect priming. Priming effects were only found when the prior context was consistent with the dominant sense of a biased ambiguous prime. The results are discussed in terms of models of ambiguity resolution: The data seem most consistent with a reordered access model.

Regressive eye movements and sentence parsing: on the use of regression-contingent analyses.

Altmann, Garnham, and Dennis (1992) recently advocated the use of a regression-contingent analysis in eye movement studies dealing with parsing of sentences containing temporary structural ambiguities. Using experimental sentences preceded by referentially supportive contexts, they demonstrated a different pattern of results when regressive eye movements were eliminated from the data set than when regressions were included. The regression-contingent analysis that they used involves an implicit assumption that regressive eye movements are a necessary consequence of subjects' being garden pathed. We report some data which demonstrate that garden path effects are sometimes even stronger in the absence of regressions and, thus, argue that readers can be garden pathed without making regressions.

Fast priming during eye fixations in reading.

Near-threshold primes were "flashed" in a target location prior to the onset of a target word while Ss read. The type and duration of the prime were manipulated. In Exp. 1, identical, related, and unrelated primes were presented for 60, 45, or 30 ms from onset of an eye fixation. The prime was then replaced with the target word, which remained in place while Ss finished reading the sentence. Fixation time on the target word was measured. Exp. 2 replicated Exp. 1, with two exceptions: A random letter string replaced the identical prime condition, and prime durations of 39, 30, or 21 ms were used. In both experiments, significant priming effects (related vs. unrelated) were obtained when the prime was presented for 30 ms. Results are discussed with regard to subliminal priming effects. Applications to the study of word recognition processes are also discussed.