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Biomedical subjects

M Badan

Publications and source records attributed to M Badan.

11 recordsLinked to original sources

Dissociated active and passive tactile shape recognition: a case study of pure tactile apraxia.

Disorders of tactile object recognition (TOR) may result from primary motor or sensory deficits or higher cognitive impairment of tactile shape representations or semantic memory. Studies with healthy participants suggest the existence of exploratory motor procedures directly linked to the extraction of specific properties of objects. A pure deficit of these procedures without concomitant gnostic disorders has never been described in a brain-damaged patient. Here, we present a patient with a right hemispheric infarction who, in spite of intact sensorimotor functions, had impaired TOR with the left hand. Recognition of 2D shapes and objects was severely deficient under the condition of spontaneous exploration. Tactile exploration of shapes was disorganized and exploratory procedures, such as the contour-following strategy, which is necessary to identify the precise shape of an object, were severely disturbed. However, recognition of 2D shapes under manually or verbally guided exploration and the recognition of shapes traced on the skin were intact, indicating a dissociation in shape recognition between active and passive touch. Functional MRI during sensory stimulation of the left hand showed preserved activation of the spared primary sensory cortex in the right hemisphere. We interpret the deficit of our patient as a pure tactile apraxia without tactile agnosia, i.e. a specific inability to use tactile feedback to generate the exploratory procedures necessary for tactile shape recognition.

Adult↗

[Role of rehabilitation in hemineglect syndromes].

Unilateral neglect syndrome compromises functional outcome of left hemiparetic patients. Treatment of this syndrome is a challenge in motor rehabilitation in order to reduce the incapacity and improve the prognosis. In this study, we present a review of the literature focusing on the different rehabilitation techniques proposed and their theoretical basis: improvement of the ability to maintain attention, improvement of spatial selective attention by implicit or explicit cueing, reduction of rightward orienting bias by sensory manipulations. Recently, we reported the improvement of symptoms of unilateral neglect syndrome after a prism adaptation to a rightward optical deviation. Unlike previous physiological manipulations used to improve neglect, this improvement lasted for at least two hours after prism removal. These results are most promising for rehabilitation programs. They may be linked to a stimulation of a short-term plasticity of brain functions and underline the interest of action in rehabilitation of neglect.

Adaptation, Physiological↗

Sequential pointing in children and adults.

The development of visuomotor control in sequential pointing was investigated in 6- to 10-year-old children and in adults. In 3 experiments we manipulated task difficulty by changing the number, the size, and the spacing of the targets in the sequences. In Experiment 4, only 1 movement was required; we varied independently the distance between targets and the distance of the starting point from the participant's body. Children's temporal and spatial parameters of the motor sequences showed large age-dependent trends, but did not reach the adult values. Comparison of performance across levels of difficulty and ages suggests that motor development is not a uniform fine-tuning of stable strategies. Instead, we argue that each stage of development is best characterized by the set of strategic components potentially available at that stage, and by the (age-dependent) rules for the selection of components in a given context.

Adult↗

Reward dependence is positively related to urinary monoamines in normal men.

According to Cloninger, three major personality dimensions, novelty seeking, harm avoidance, and reward dependence, are dependent on central monoaminergic systems. This study examined the relationship between the urinary levels of different monoamines and the above personality dimensions. Fifty normal men answered the Tridimensional Personality Questionnaire (TPQ); their levels of dopamine, norepinephrine, epinephrine, normetanephrine, metanephrine, 3-methoxy-4-hydroxyphenylglycol, vanilmandelic acid, homovanilic acid, and serotonin metabolite 5-hydroxyindolacetic acid were measured in urine on two consecutive nights. Significant and positive correlations were found between reward dependence, 3-methoxy-4-hydroxyphenylglycol, and epinephrine (r = .50 and r = .51, respectively). Monoamine levels explained 44% of the variance of reward dependence. Cluster analysis identified three groups of subjects presenting specific patterns of monoamine excretion. The TPQ scores could discriminate among subjects belonging to these clusters. These results point out a narrow relationship between urinary monoamine excretion and the basic personality dimension of reward dependence.

Adult↗

Relationship between the prescriber's instructions and compliance with antibiotherapy in outpatients treated for an acute infectious disease.

Antibiotics are frequently prescribed in everyday practice for the management of acute microbial infections. The present study was designed to assess the relationship between the prescriber's instructions and the patient's adherence to a prescribed schedule of twice-daily doses of antibiotic for at least 5 days to treat an infectious disease. The trial was conducted by ten practicing physicians on ambulatory patients. Compliance with the antibiotic regimen was evaluated using a microelectronic device, the Medication Event Monitoring System (MEMS). Seventy patients were prescribed an antibiotic in twice-daily doses for 5 to 14 days (mean = 8). Data were available for analysis from 68 of them, aged 18 to 84 years (mean = 44). The "taking compliance" for the whole story group, which corresponded to the ratio of the number of times the bottle was opened and the total number of doses prescribed during the monitoring period, was nearly perfect at 99.6%. However, only 32.6% of the medications was taken within 1 hour before or after the 12-hour interval expected to be optimal for a twice-daily regimen. It therefore seems highly desirable that physicians give more detailed recommendations to their patients regarding the drug regimens they prescribe.

Adolescent↗

Haptic processing by the left hemisphere in a split-brain patient.

We report the case of a patient who suffered an ischemic accident resulting in damage to the anterior part of the corpus callosum and to the white matter in the posterior right hemisphere. Recognition of two-dimensional haptic stimuli explored with the right hand was severely impaired. The deficit was not specific to the type of stimuli, since letters, digits and geometrical shapes were not correctly recognized. Poor performance was not due to a specific mode of haptic exploration, since deficits were also observed without active manipulation of the stimuli. In contrast, the patient correctly named visual letters presented in the right visual hemifield (left hemisphere), and recognized three-dimensional common objects palpated with the right hand. Comparable results were observed in a surgical split-brain patient tested as a control. We conclude that (i) the construction of spatial representations of haptic stimuli, such as two-dimensional stimuli or three-dimensional block letters, cannot be fully realized in the intact left hemisphere, this ability requiring the contribution of both hemispheres, and (ii) tests for correct naming of common objects do not provide sufficient evidence to establish the integrity of the system involved in the identification of haptic information processed by the right hand of split-brain patients.

Adult↗

Effects of one-year hyposensitization in allergic rhinitis. Comparison of two house dust mite extracts.

In an open study, 21 patients suffering from chronic non-seasonal rhinitis and allergic to house mites (HDM) have been treated for 1 year with either a new extract (Pharmalagen; n = 10) or an allergoid, pyridine denatured, extract (Alavac; n = 11), both precipitated with AlOH3 (depot). The following investigations were performed before and after therapy: clinical scoring (for 4 weeks), quantified skin prick tests (SPT) and nasal provocation tests (NPT) with HDM, and determination in serum of HDM-specific IgE and IgG. Both groups were compared with six patients who remained untreated and underwent the same investigations. Hyposensitization with either extract induced an improvement in clinical scores (P less than 0.05), a decrease in SPT reactivity (Pharmalgen: P less than 0.001; Alavac: P less than 0.01), a marked increase in the nasal tolerance to HDM (P less than 0.001) and in HDM-specific IgG (P less than 0.001). In the group of untreated patients, all these parameters remained unchanged. Compared with the Alavac extract, the Pharmalgen extract was more active in decreasing SPT reactions (P less than 0.05) and inducing a HDM-specific IgG rise (P less than 0.05). Although both extracts induced some untoward allergic reactions, no adrenaline was used at any time during the study. These data suggest that hyposensitization with depot extracts of HDM can be considered a safe and active adjunct to the treatment of allergic rhinitis.

Adolescent↗

Respiratory acoustical impedance: a new technique to measure airway response during bronchial inhalation challenges.

Respiratory acoustical impedance, a new method to measure airway obstruction during quiet breathing, was compared with plethysmography and spirometry in 19 asthmatics undergoing a bronchial inhalation challenge with an allergen. Respiratory acoustical impedance and plethysmography were both more sensitive than spirometry in detecting bronchoconstriction. Respiratory acoustical impedance is easily measured during quiet breathing, even in uncooperative subjects; forced expirations, which may alter bronchial tone, are avoided. Respiratory acoustical impedance is sensitive and reliable in measuring acute airway obstruction.

Acoustic Impedance Tests↗

Anisoylated plasminogen streptokinase activator complex versus streptokinase in acute myocardial infarction. Preliminary results of a randomised study.

25 patients with acute myocardial infarction pain lasting more than 20 minutes which was not relieved by nitrates, whose ECGs showed ST segment elevations of 1 mm or more in 2 or more ECG leads, and who presented less than 3 hours after onset of their symptoms were randomly assigned to one of 2 thrombolytic treatment groups: a single intravenous bolus of anisoylated plasminogen streptokinase activator complex (APSAC) 30U in 5 minutes or an intravenous infusion of streptokinase 1,500,000U over 60 minutes. 3 to 4 hours after the administration of the thrombolytic agent, all patients received intravenous heparin at full dosage for 24 hours. The patency of the infarct-related coronary vessels was assessed by angiography 1 to 4 hours after administration of the thrombolytic agent. Clinical signs, ECGs, pulse, blood pressure and temperature were monitored regularly for 24 hours after treatment or as clinically appropriate. APSAC seemed to be at least as effective as streptokinase in terms of patency of the infarct-related vessel (92% vs 63%, respectively). The adverse events were similar and none was life-threatening. APSAC and streptokinase caused similar falls in blood fibrinogen levels. APSAC, given as a bolus injection over 5 minutes, was easier to administer than streptokinase, which was given as an infusion during 60 minutes.

Adult↗

[Prospective study of the undesirable effects of allergic desensitization].

Untoward allergic reactions were monitored prospectively in 98 patients undergoing hyposensitization with depot type preparations of house dust mites (42 patients) or grass pollens administered before the pollen season (56 patients). 44% of the patients experienced at least one major local reaction, usually when injected with high doses of allergens. A mild systemic reaction (benign crisis of rhinitis or asthma within 12 hours after the injection) was reported at least once by 9% of the pollen-treated and 52% of the mite-treated patients. A severe systemic reaction, which improved rapidly with adrenaline, was noted in 3% of the pollen-treated and 5% of the mite-treated patients. These data indicate that untoward allergic reactions during hyposensitization are not uncommon, and this type of treatment therefore requires a strict indication.

Allergens↗