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PubMed1995

Parkinson's disease affects automatic and spares intentional verbal learning. A stochastic approach to explicit learning processes.

We studied word list and paired associates learning in patients with idiopathic Parkinson's disease and normal controls by means of a two-stage stochastic model, which allows independent measurements of encoding, storage and retrieval abilities. We preliminarily ascertained that the model components were both sufficient and necessary to account for the overall performance of the subjects, and then compared the learning abilities between the two groups. Parkinson's disease patients were selectively impaired in identifying well-known engrams, for which learning is superfluous, and in automatic retrieval, namely in abilities that do not need attentional effort. By contrast, they were unimpaired in encoding and intentional retrieval, which require a purposeful effort. The automatic-voluntary dissociation of Parkinson's disease patients' motor behaviour is, therefore, paralleled by some features of their memory performance.

Aged↗
PubMed2002

Transcervical needle biopsy of uterine myoma-like tumors using an automatic biopsy gun.

OBJECTIVE: To describe a practical procedure of transcervical needle biopsy of uterine myoma-like tumors using an automatic biopsy gun and its potential risks. DESIGN: Description of new biopsy procedure. SETTING: University teaching hospital. PATIENT(S): Three hundred twelve patients who had been recommended for surgery for uterine myoma-like tumors by the hospital's outside doctors. INTERVENTION(S): Transcervical needle biopsy of uterine myoma-like tumors. MAIN OUTCOME MEASURE(S): Successful sampling rate, duration of procedure, estimated blood loss, patient discomfort, and complications. RESULT(S): Of the 312 patients who underwent transcervical needle biopsy, specimens were obtained from 311 (99.7%). The mean (+/- SD) duration of procedure was 6.3 +/- 5.2 minutes. The mean estimated blood loss was 10.4 +/- 10.9 g. There were two cases (0.6%) in which the blood loss during the procedure was in excess of 50 g, but bleeding can be conservatively controlled in such cases with an intrauterine tamponade using gauze or a balloon catheter. The level of patient pain and discomfort during the needle biopsy was significantly lower than that during endometrial curettage. No major complications requiring surgery occurred. CONCLUSION(S): Transcervical needle biopsies of uterine myoma-like tumors using an automatic biopsy gun are practical, simple, and safe. This new procedure can be of routine clinical use.

Adult↗
PubMed1979

Effect of the autonomic blockade on the automaticity of the A-V junctional pacemaker in awake dogs.

The effect of the autonomic blockade on the automaticity of the A-V junctional pacemaker was evaluated in 15 awake dogs with experimentally induced A-V junctional rhythm. The duration of asystole after overdrive (D.A.O.) in these dogs was prolonged significantly in accordance with increase in the drive rate, and the mean +/- SD of the D.A.O. reached 4.7 +/- 1.1 seconds (N = 15) after overdrive at 2.5 times the spontaneous heart rate. After administration of atropine (0.4 mg/kg; i.v.) to eight dogs, the mean +/- SD of the D.A.O. at the same rate decreased from 4.5 +/- 0.9 to 3.4 +/- 1.2 seconds. After administration of practolol (0.5 mg/kg; i.v.) to the seven other dogs, the mean +/- SD of the D.A.O. at the same rate increased remarkably from 4.9 +/- 1.3 to 9.4 +/- 3.0 seconds. Intravenous injection of practolol (0.5 mg/kg) had no effect upon the D.A.O. in the five dogs with sinus rhythm. Thus, it is suggested that (1) the sympathetic nerve might play a more important role in regulating the automaticity of the A-V junctional pacemaker than the vagus and (2) it physiologically might take over 5.0 seconds for the A-V junctional pacemaker to initiate an escape beat during longstanding sinus arrest, if a marked dysfunction of the A-V junctional pacemaker occurs due to a decrease in tension of the sympathetic nerve.

Animals↗
PubMed1996

Complete infrahisian atrioventricular block after endocavitary shock delivered by an automatic implantable cardiac defibrillator.

Transient reproducible complete infrahisian atrioventricular block occurred after endocavitary cardioversion of ventricular tachycardia and ventricular fibrillation by an automatic implantable cardiac defibrillator in a patient with left bundle branch block and baseline borderline H-V interval. Six months later, a permanent complete atrioventricular block occurred after repetitive endocavitary shocks. Several hypothetical mechanisms may explain this infrahisian atrioventricular block a "fatigue" phenomenon of the His-Purkinje system, vagally mediated atrioventricular block, and/or ablation of the His conduction system. The last seems to be the most probable, which would justify implantation of an automatic implantable cardiac defibrillator with backup pacing in all patients, especially in the presence of bundle branch block.

Adult↗
PubMed2003

Automatic methods for predicting functionally important residues.

Sequence analysis is often the first guide for the prediction of residues in a protein family that may have functional significance. A few methods have been proposed which use the division of protein families into subfamilies in the search for those positions that could have some functional significance for the whole family, but at the same time which exhibit the specificity of each subfamily ("Tree-determinant residues"). However, there are still many unsolved questions like the best division of a protein family into subfamilies, or the accurate detection of sequence variation patterns characteristic of different subfamilies. Here we present a systematic study in a significant number of protein families, testing the statistical meaning of the Tree-determinant residues predicted by three different methods that represent the range of available approaches. The first method takes as a starting point a phylogenetic representation of a protein family and, following the principle of Relative Entropy from Information Theory, automatically searches for the optimal division of the family into subfamilies. The second method looks for positions whose mutational behavior is reminiscent of the mutational behavior of the full-length proteins, by directly comparing the corresponding distance matrices. The third method is an automation of the analysis of distribution of sequences and amino acid positions in the corresponding multidimensional spaces using a vector-based principal component analysis. These three methods have been tested on two non-redundant lists of protein families: one composed by proteins that bind a variety of ligand groups, and the other composed by proteins with annotated functionally relevant sites. In most cases, the residues predicted by the three methods show a clear tendency to be close to bound ligands of biological relevance and to those amino acids described as participants in key aspects of protein function. These three automatic methods provide a wide range of possibilities for biologists to analyze their families of interest, in a similar way to the one presented here for the family of proteins related with ras-p21.

Algorithms↗
PubMed1990

Automatic definition of recurrent local structure motifs in proteins.

An automatic procedure for defining recurrent folding motifs in proteins of known structure is described. These motifs are formed by short polypeptide fragments of equal size containing between four and seven residues. The method applies a classical clustering algorithm that operates on distances between selected backbone atoms. In one application, we use it to cluster all protein fragments into only four structural classes. This classification is rough considering the observed diversity of local structures, but comparable in homogeneity to the four classes of secondary structure (alpha-helix, beta-strand, turn and coil). Yet, it discriminates between extended and curved coil and distinguishes beta-bulges from beta-strands. In a second application, the clustering procedure is combined with assignment of backbone dihedral angles to allowed regions in the Ramachandran map. This produces an exhaustive repertoire of highly homogeneous families of structural motifs that contains all the beta-hairpins, beta alpha- and alpha beta-loops previously defined by manual procedures, and new structural families of which two examples, a beta alpha-loop and an alpha-helix beginning, are analyzed in detail. The described automatic procedures should be useful in categorizing structure information in proteins, thereby increasing our ability to analyze relations between structure and sequence.

Amino Acid Sequence↗
PubMed1996

Rapid-processing procedure for heat polymerization of polymethyl methacrylate in a pressure cooker with automatic controls.

This study introduces a new rapid-processing procedure for curing polymethyl methacrylate denture base resin in an automatically controlled pressure cooker. The cooker filled with water was inflated with 6 kgf/cm2 air pressure and heated to 120 degrees C (248 degrees F) and maintained for 10 minutes. No significant differences were found between the new pressure cooker method and the conventional method for surface hardness and porosity (p > 0.05). The pressure cooker significantly shortened polymerization time, and the polymerization is controlled automatically.

Air Pressure↗
PubMed1991

Ultrasound guided percutaneous renal biopsy using an automatic core biopsy system.

With real-time ultrasound visualization and an automatic core biopsy system 23 percutaneous renal biopsies were performed with the use of local anesthesia in 22 patients. Adequate tissue for diagnosis was obtained in all 23 cases, with 1 patient undergoing bilateral renal biopsy and 1 requiring repeat biopsy. One patient had an asymptomatic perirenal hematoma and 1 experienced a single episode of transient gross hematuria. There were no major complications. The use of an automatic core biopsy system guided by real-time ultrasound is an important technique that may be added to the urological armamentarium.

Anesthesia, Local↗
PubMed2001

Reduced skilfulness of arm motor behaviour among motor stroke patients with good clinical recovery: does it indicate reduced automaticity? Can it be improved by unilateral or bilateral training? A kinematic motion analysis study.

Functional cortical reorganisation had been demonstrated to accompany recovery from motor stroke. In agreement with a previous study, quantitative kinematic analysis of aimed movements in 14 almost completely recovered hemiparetic stroke patients and 14 healthy control subjects indicated a reduced skilfulness of both the more ballistic initial movement phase and the more feedback-guided late homing-in phase of aimed movements. By means of two dual motor tasks it was further investigated whether the reduced skilfulness of patients was due to an increased attentional demand and thus a reduced automaticity of motor control. Interference effects by dual tasks, however, were similar for patients and control subjects. Thus, the notion of reduced automaticity could not be supported empirically, and reduced skilfulness seemed rather related to residual pyramidal motor deficits. By means of a repetitive daily training for 1 week based on the Arm Ability Training approach, patients were able to reduce their performance deficits in both movement phases significantly. Whether patients practised with the affected arm or simultaneously with both the affected and non-affected arm only marginally modified outcome, unilateral training being slightly more efficacious. These findings demonstrate that even clinically minor residual motor deficits can be improved by a structured training for the affected arm.

Adult↗
PubMed2002

Evidence for a selective deficit in automatic activation of positive information in patients with Alzheimer's disease in an affective priming paradigm.

Using an affective priming paradigm, we studied the automatic and unconscious activation of emotional information in long-term memory. Participants had to judge target words preceded by various primes as positive or negative. The primes were masked and the SOA between the onset of primes and the onset of targets was 50 ms. Our results showed that in patients with dementia of the Alzheimer type (DAT), the negativity bias was preserved and the emotional priming effect was perturbed with positive targets. In control participants, this priming effect was restricted to negative targets. These findings are discussed in terms of preserved automatic activation of emotional information in Alzheimer's disease (AD) and in terms of an early deficit of the left hemisphere in AD making positive information more vulnerable to disease.

Aged↗
PubMed1998

Role of the striatum, cerebellum and frontal lobes in the automatization of a repeated visuomotor sequence of movements.

Recently, Doyon et al. [20] demonstrated that lesions to both the striatum and to the cerebellum in humans produce a similar deficit in the learning of a repeated visuomotor sequence, which occurs late in the acquisition process. We now report the results of two experiments that were designed to examine whether this impairment was due to a lack of automatization of the repeating sequence of finger movements by using a dual-task paradigm and by testing for long-term retention of this skill. In Experiment 1, the performance of groups of patients with Parkinson's disease, or with damage to the cerebellum or to the frontal lobes, was compared to that of matched control subjects on the Repeated Sequence Test (primary task) and the Brooks' Matrices Test (secondary task). These two tests were administered concomitantly in both early and late learning phases of the visuomotor sequence. Overall, the groups did not differ in their ability to execute the primary task. By contrast, in accordance with the predictions, patients in Stages 2-3 of Parkinson's disease or with a cerebellar lesion failed to reveal the expected increase in performance on the secondary task seen with learning, suggesting that the latter groups of patients did not have access to the same level of residual cognitive resources to complete the matrices compared to controls. In Experiment 2, the same groups of patients and control subjects were retested again 10-18 months later. They were given four blocks of 100 trials each of the repeating sequence task, followed by a questionnaire and a self-generation task that measured their declarative knowledge of that sequence. The results revealed a long-term retention impairment only in patients who changed from Stage I to Stage II of the disease (suggesting further striatal degeneration) during the one-year interval, or who had a cerebellar lesion. By contrast, performance of the three clinical groups did not differ from controls on declarative memory tests. These findings suggest that both the striatum and the cerebellum participate to the automatization process during the late (slow) learning stage of a sequence of finger movements and that these structures also play a role in the neuronal mechanism subserving long-term retention of such a motor sequence behavior.

Adult↗
PubMed1980

Comparison of films processed in automatic and manual processors.

This study compared the quality of Kodak RP X-Omat, Kodak Blue Brand, and Kodak periapical films processed in manual tank. Auveloper, P-10, All-Pro, Philips 810, and RP X-Omat processors. Film quality was evaluated in terms of film fog, image contrast, and resolution. For Kodak RP X-Omat and periapical films, automatic processors produced less film fog and were more consistent in fog production than manual tank processor. The difference in fog production between automatic and manual processors was not clinically significant; indeed, it was visuially undetectable. The difference disappeared when Kodak Blue Brand film was used. For Kodak RPX-Omat and Kodak Blue Brand films, at high film densities, the RP X-Omat processor produced films of the highest image contrast. For periapical films, the manual processor produced the highest image contrast. Image contrast at low densities was nearly the same for all processors. For each type of film, resolution was nearly the same for all processors.

Radiography, Dental↗
PubMed2004

Electrophysiological evidence of automatic early semantic processing.

This study investigates the automatic-controlled nature of early semantic processing by means of the Recognition Potential (RP), an event-related potential response that reflects lexical selection processes. For this purpose tasks differing in their processing requirements were used. Half of the participants performed a physical task involving a lower-upper case discrimination judgement (shallow processing requirements), whereas the other half carried out a semantic task, consisting in detecting animal names (deep processing requirements). Stimuli were identical in the two tasks. Reaction time measures revealed that the physical task was easier to perform than the semantic task. However, RP effects elicited by the physical and semantic tasks did not differ in either latency, amplitude, or topographic distribution. Thus, the results from the present study suggest that early semantic processing is automatically triggered whenever a linguistic stimulus enters the language processor.

Adolescent↗
PubMed2003

Automatic recognition of explorative strategies in the Morris water maze.

Notwithstanding the development of reliable tracking systems, the quantification methodology of the Morris water maze (MWM) has witnessed an operational mismatch between the indexes used to quantify MWM performance and the cognitive concepts derived from these indexes. Indeed, escape latency is the main, and often unique, performance measure used for the quantification of behavior. Aim of the present work was to overcome this limitation by presenting a methodology that allows for automatic categorical pattern recognition of the behavioral strategies performed in the MWM. By selecting few a priori and user-defined behavioral categories, many quantitative variables and regions of interest (ROIs), we used discriminant analysis (DA) to obtain 97.9% of correct automatic recognition of categories. The developed discriminant model (DM) also allowed to predict category membership of newly recorded swim paths with the same statistical efficacy (96%), and to identify the variables that better discriminate between adjacent categories. The combination of DA with a tracking system, a selection of many variables, different ROIs and qualitative categorization, reduces the gap between the measurement process and the categories used to describe a given behavior, and offers a methodology to computationally reproduce the human categorization of behaviors in the MWM.

Animals↗
PubMed2003

Automatic quantitation of HIV-1 mediated cell-to-cell fusion with a digital image analysis system (DIAS): application for rapid screening of HIV-1 fusion inhibitors.

Human immunodeficiency viruses type 1 (HIV-1) mediated cell-to-cell fusion plays an important role in HIV-1 spread from infected cells to uninfected cells and in HIV-1 cytopathogenesis. In the present study, we developed a convenient cell fusion assay using a computer-controlled digital image analysis system (DIAS) for automatic quantitation. Compared with a manual quantitative method, DIAS automatic method is less laborious, and more rapid. Furthermore, it is more objective and less dependent on the researchers' experience. This method has great potential to be developed further as a high-throughput screening assay for rapid screening of HIV-1 fusion inhibitors, for evaluating the activity of HIV-1 entry inhibitors and for studying the mechanism of action of anti-HIV-1 agents.

Cell Fusion↗
PubMed2002

QT dispersion measured by an automatic continuous method early in patients admitted for chest pain.

BACKGROUND: There is a need for risk markers in patients with acute chest pain. QT dispersion (QTd) is a prognostic marker in several groups of patients. A problem with the manual measurement of QTd is operator dependency. This can be avoided by using an automatic method. We investigated QTd, derived from multiple automatic measurements, as a risk marker in a population with chest pain. METHODS: In 548 patients admitted to the coronary care unit for chest pain and nondiagnostic ECG, 12-lead ECG recordings were collected each minute during the initial 17 h. From recordings with > or =10 valid leads, mean QTd (QTdMean), QTd in the first satisfactory recording and estimates of variability of QTd were computed and correlated to outcome. RESULTS: In the group with QTdMean > or =40 ms (n=277), 10 patients died during the initial 30 days; one patient died in the group with QTdMean <40 ms (n=271) (P=0.07). During follow-up (median 6 months), 19 vs. five patients died in each group (P=0.03). The figures for the triple endpoint death/myocardial infarction/revascularisation were 52 vs. 27 events during the initial 30 days (P=0.018) and 76 vs. 41 events during follow-up (P=0.003). QTd in the first recording did not predict new cardiac events. CONCLUSIONS: QTd measured as the mean value of multiple recordings was found to be a powerful marker for cardiac events during follow-up. It was superior to the analysis of QTd in a single ECG. It can be used for the selection of low-risk patients, but was not effective in identifying high-risk patients.

Aged↗
PubMed1999

Automatic attentional shifts induced by a noradrenergic drug in Alzheimer's disease: evidence from evoked potentials.

Prior research showed that attentional deficits are observed in Alzheimer's disease (AD). These deficits can further impair other cognitive processes. The present experiment was designed to study the shifts in attention induced by a noradrenergic drug (S 12024-2) through their electrophysiological correlates in 12 outpatients with mild AD, using an auditory oddball paradigm. The P3a component, known to be related to automatic attentional processing, was increased by the drug, whereas no changes occurred either in PN or in P3b, which are considered to reflect conscious processing. These results point to an involvement of the noradrenergic system in the modulation of automatic attentional processing, and provide evidence for weakening of the orienting reflex in AD, due to a possible noradrenergic deficit in patients with mild AD.

Adrenergic Agents↗
PubMed1998

Automatic and effortful processes in auditory memory reflected by event-related potentials. Age-related findings.

Mismatch negativity (MMN) and N2b were elicited during a selective dichotic-listening task in 16 young (Y), 16 middle-aged (M) and 19 elderly (E) subjects to evaluate automatic and effortful memory comparison of auditory stimuli. Sequences of standard (80%) and deviant (20%) tones were dichotically presented to subjects in two runs. In each run, subjects were instructed to give a button-press response to the deviant (target) tones in the ear designated as attended and to ignore the input to the other ear. Peak latencies, peak amplitudes and mean amplitudes were calculated for MMN and N2b components in each subject. MMN latency and amplitude were quite stable regardless of age, while N2b latency was significantly longer in M and E subjects than in Y subjects. These results are interpreted as reflecting that automatic processes of comparison in auditory memory of stimuli presented at short interstimulus intervals remain quite stable from 23 to 77 years of age; however, those requiring attentional effort decline with age.

Acoustic Stimulation↗