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Biomedical subjects

M Leclercq

Publications and source records attributed to M Leclercq.

At least 19 recordsLinked to original sources
PubMed2004

Right spatial neglect after left hemisphere stroke: qualitative and quantitative study.

OBJECTIVES: Comparatively little research has been conducted on right neglect after left brain damage. The authors sought to assess contralateral neglect in subacute left hemisphere stroke patients using a comprehensive test battery validated in a large control group after right hemisphere stroke. METHODS: Seventy-eight left hemisphere stroke patients were assessed. The test battery included a preliminary assessment of anosognosia and visual extinction, a clinical assessment of gaze orientation and personal neglect, and paper-and-pencil tests of spatial neglect in the peripersonal space. Only nonverbal tests were used. RESULTS: Drawing and cancellation tasks revealed neglect in 10 to 13% of patients. The combined battery was more sensitive than any single test alone. A total of 43.5% of patients showed some degree of neglect on at least one measure. Anatomic analyses showed that neglect was more common and severe when the posterior association cortex was damaged. CONCLUSIONS: The frequency of occurrence of right neglect was, as expected, much lower than that reported in a study using the same assessment battery in right brain damage stroke patients. Nevertheless, neglect was found in a substantial proportion of patients at a subacute stage, suggesting that it should be considered in the rehabilitation planning of left brain damage stroke patients.

Awareness↗
PubMed2002

Sensitivity of clinical and behavioural tests of spatial neglect after right hemisphere stroke.

OBJECTIVES: The lack of agreement regarding assessment methods is responsible for the variability in the reported rate of occurrence of spatial neglect after stroke. The aim of this study was to assess the sensitivity of different tests of neglect after right hemisphere stroke. METHODS: Two hundred and six subacute right hemisphere stroke patients were given a test battery including a preliminary assessment of anosognosia and of visual extinction, a clinical assessment of gaze orientation and of personal neglect, and paper and pencil tests of spatial neglect in the peripersonal space. Patients were compared with a previously reported control group. A subgroup of patients (n=69) received a behavioural assessment of neglect in daily life situations. RESULTS: The most sensitive paper and pencil measure was the starting point in the cancellation task. The whole battery was more sensitive than any single test alone. About 85% of patients presented some degree of neglect on at least one measure. An important finding was that behavioural assessment of neglect in daily life was more sensitive than any other single measure of neglect. Behavioural neglect was considered as moderate to severe in 36% of cases. A factorial analysis revealed that paper and pencil tests were related to two underlying factors. Dissociations were found between extrapersonal neglect, personal neglect, anosognosia, and extinction. Anatomical analyses showed that neglect was more common and severe when the posterior association cortex was damaged. CONCLUSIONS: The automatic rightward orientation bias is the most sensitive clinical measure of neglect. Behavioural assessment is more sensitive than any single paper and pencil test. The results also support the assumption that neglect is a heterogeneous disorder.

Activities of Daily Living↗
PubMed2001

[Presenting a battery for assessing spatial neglect. Norms and effects of age, educational level, sex, hand and laterality].

The aim of this study was to build up a battery for assessing spatial neglect, then to analyse the norms and potential effects of age, education level, sex, hand used, and laterality. It was also to contribute evaluating the pseudoneglect phenomenon described by Heilman, which consists in a tendency of normal subjects to neglect the right peripersonal space. Tasks selected were presented to important groups of normal subjects, most often larger than 450. The battery comprised of a bell cancellation test, scene copy, clock drawing, two line bisection tasks, identification of overlapping figures, text reading, writing task, and the representational task of the France map. For each of them, different variables were selected, especially investigating the difference between performance in the right and the left hemispaces. This study allowed defining the threshold values (percentiles 5 and 95) for deciding of the pathological character of a patient performance. It also showed that the pseudoneglect phenomenon is more obvious in some tasks such as line bisection, and probably also in the representational task of the France map and writing. His importance and at times his side were influenced by the factors we studied, with between tasks differences, but also by the nature of the task to be performed, and especially his verbal component.

Adult↗
PubMed2000

Mammalian FKBP-25 and its associated proteins.

Soluble proteins from porcine brain were divided into two packs: (1) proteins which pass freely through CM52-cellulose, and (2) proteins retained on CM52. Each of these two packs of proteins was fractionated on preparative flat-bed isoelectrofocusing gel in the range of pH 2-12. Native FKBP-25 and its truncated forms were found among other proteins retained on CM52-cellulose. Immunoblotting with anti-FKBP-25 showed two bands in the range 27-30 kDa, one due to unmodified FKBP-25 and other due to FKBP-25 mixed with high-mobility group II protein (HMG-II). Selective immunostaining with anti-FKBP-25 antibodies of proteins which were not retained on CM52-cellulose showed several bands within the range of pI 7-5 and mass of 23 +/- 2 kDa. These fractions of proteins were next resolved on two-dimensional gels and immunostained with anti-FKBP-25 antibodies. Six proteins in the pI range 7-5 were detected. Edman degradation of alpha-chymotrypsin digests of the major spot suggests that it contains the GTP-binding protein Rab5 co-migrating with guanylyl kinase, whereas MALDI-TOF showed that a residual content of FKBP-25 may be also associated with these two proteins. A residual quantity of FKBP-25 was also associated with the phosphatidylethanolamine-binding protein which is abundant in the brain.

Alkaline Phosphatase↗
PubMed2000

The anatomy of aphasia revisited.

OBJECTIVE: To determine lesion locations associated with the various types of aphasic disorders in patients with stroke. BACKGROUND: The anatomy of aphasia has been challenged by several recent studies. Discrepancies are likely to be due to methodologic issues. METHODS: We examined 107 patients with a standardized aphasia battery and MRI. Three examiners blinded to the clinical data rated signal abnormalities in 69 predetermined regions of interest. The statistical procedure used classification tree testing, which selected regions associated with each aphasic disorder. RESULTS: 1) Nonfluent aphasia depended on the presence of frontal or putaminal lesions; 2) repetition disorder on insula-external capsule lesions; 3) comprehension disorder on posterior lesions of the temporal gyri; 4) phonemic paraphasia on external capsule lesions extending either to the posterior part of the temporal lobe or to the internal capsule; 5) verbal paraphasia on temporal or caudate lesions; and 6) perseveration on caudate lesions. These analyses correctly classified 67% to 94% of patients. CONCLUSIONS: Lesion location is the main determinant of aphasic disorders at the acute stage. Most clinical-radiologic correlations supported the classic anatomy of aphasia.

Adolescent↗
PubMed2000

Patterns of attentional impairment following closed head injury: a collaborative European study.

A comprehensive assessment of both selective (focused attention, divided attention) and intensive (alertness and vigilance) attentional processes was performed on 106 patients with closed head injury using a computerised battery for the evaluation of attention. All patients were tested at least five months after their accident. A high percentage of patients were pathological in tests mapping the selective components of attention while only a minority were impaired on tests mapping the intensive components of attention. Three different subgroups of patients with consistent performance patterns were evidenced. The psychometric characteristics of the battery and its possible clinical usefulness are discussed.

Adult↗
PubMed2000

Dual task performance after severe diffuse traumatic brain injury or vascular prefrontal damage.

The ability to perform two tasks simultaneously is a key function of the central executive of working memory (Baddeley, 1986). This study addressed dual-task performance after diffuse very severe traumatic brain injury (TBI) (mean coma duration = 21 days, mean post-traumatic amnesia = 70 days) or prefrontal damage due to a ruptured aneurysm of the anterior communicating artery (AACA). Mean time since injury was 8 and 16 months in the TBI and the AACA group respectively. A simple visual reaction time and random number generation were used as single and dual tasks. Randomization was self-paced, to control for individual differences in speed. Both patient groups had greater reaction time decrements than controls under the dual-task condition, suggesting a divided attention deficit. In addition, patients with AACA performed significantly poorer in random generation. These results suggest that patients with AACA and with severe TBI suffer from an impairment of the central executive system.

Adult↗
PubMed1997

Subjective experience in brain-injured patients and their close relatives: a European Brain Injury Questionnaire study.

Results are reported from an international project the aim of which has been to develop and validate a wide-ranging questionnaire suitable for administration to brain-injured patients and their relatives. A self-report questionnaire concerning subjective experience of cognitive, emotional and social difficulties (The European Brain Injury Questionnaire, EBIQ) was administered to a group of 905 brain-injured patients, and close relatives to these competed a parallel version of the questionnaire concerning the brain-injured person. The sample was drawn from seven European countries together with Brazil. The same questionnaire was also administered to a group of 203-non-brain-injured controls, similarly in self-report and relative-report versions. Scales relating to eight specific areas of functioning, together with a global scale, are derived from the questionnaire and their internal reliability was estimated in the present data. Analyses of the 63 items of the questionnaire showed consistently greater levels of problems for the brain-injured group, especially as indicated by relatives. This pattern was substantially replicated among the nine scales. The scales discriminated well between stroke patients and those who had suffered a traumatic brain injury. There was also a tendency for reported problems to be greater for patients who were surveyed later post-injury (> or = 19 months) rather than earlier. Comparison of sets of controls derived from two countries (France and Brazil) showed small but important differences. It is concluded that the questionnaire has an acceptable reliability and validity, but that it will be necessary to obtain culturally relevant non-brain-injured control data when employing it in different countries.

Adolescent↗
PubMed1996

New records of Tabanidae (Diptera) from Saudi Arabia, first record of Atylotus venturii Leclercq and Tabanus separatus Efflatoun.

Atylotus venturii Leclercq and Tabanus separatu Efflatoun (Diptera: Tabanidae) are 2 additional species in Saudi Arabia; they lift up to 26 taxa known from the country. Some comments on new record of other species, zoogeographical distribution of Tabanus sufis, taxonomic significance of eye pattern of Tabanidae, exemplification with T. albifacies and T. unifasciatus, rehydration of dry specimens, are presented.

Animals↗
PubMed1995

Production of a new monoclonal antibody specific to human des-gamma-carboxyprothrombin in the presence of calcium ions. Application to the development of a sensitive ELISA-test.

In order to explore pathologies possibly associated with vitamin K deficiency, several monoclonal antibodies (mAbs) were produced against human Desgamma-Carboxy-Prothrombin (DCP). One of these mAbs, designated C4B6, detected DCP forms in the presence of Calcium ions, confirmed by comparison with the patterns of two electrophoretic techniques: Affino-Immuno-Electrophoresis (CAIE) and Polyacrylamide Gel Electrophoresis followed by Electro-blotting (PAGE-Blot). An Enzyme-Linked-Imunosorbent Assay (ELISA) using mAb C4B6 has been developed, optimized and standardized. It has proven to be specific for DCP forms and has a minimum sensitivity of 0.156 A.U/ml.

Animals↗
PubMed1995

In vitro and in vivo antifilarial activity of ethynesulfonamides, epoxyethanesulfonamides and carboxamide analogues.

A series of 2-substituted trans-1,2-epoxyethanesulfonamides (1T), ethynesulfonamides (2), and their carboxamide analogues 3 (cis and trans) and 4 were evaluated for their antifilarial activity, first in vitro against the infective larvae of the filaria Molinema dessetae, then in vivo against the same filaria in Proechimys oris, its natural host. On the whole, compounds 2 displayed a high level of activity in vitro, while 4 showed a wider range and 3 were virtually inactive. The modest activity found within the series 1T was assumed to be due, in part, to the instability of the products under the conditions of the biological tests. Five new compounds within the series 1T, 2 and 4 showed a macrofilaricidal activity in vivo. There is no clear correlation between in vivo and in vitro data. It was observed, however, that within the series 2 and 4 all the compounds active in vivo were among the most potent compounds in vitro. Nevertheless, the in vitro model, although of limited value, could help in selecting compounds for further evaluation within a given series.

Aedes↗
PubMed1994

Mechanism of the abnormal vitamin K-dependent gamma-carboxylation process in human hepatocellular carcinomas.

BACKGROUND: An important marker for hepatocellular carcinoma is the presence of des-gamma-carboxy (abnormal) prothrombin. However, the molecular basis for the reduced carboxylation of prothrombin is unknown. METHODS: Two groups of patients were defined according to the absence (Group I, n = 7) or presence (Group II, n = 8) of des-gamma-carboxy prothrombin. The enzymatic activity of gamma-carboxylase and the total microsomal prothrombin concentration were determined in all tumors. The kinetic parameters for the synthetic peptide Phe-Leu-Glu-Glu-Leu (FLEEL) were measured in eight tumors. The gamma-carboxylase mRNA expression was evaluated by Northern blot analysis in 12 of 15 tumors. In addition, the total vitamin K content (K1, K1 epoxide, and menaquinones 4-10) in 10 tumors was investigated by high performance liquid chromatography. RESULTS: Concentrations of menaquinones 4-10 were normal in the nontumorous part of the liver but significantly decreased (P = 0.02) in all the tumors (Groups I and II). This decrease was more severe in Group II (P = 0.02). The tumors in Group I had normal or increased gamma-carboxylase activity and increased mRNA expression (P < 0.02) as compared with their nontumorous counterparts. The tumors in Group II were heterogeneous. Five tumors displayed low gamma-carboxylase activity, associated with low mRNA expression in two, whereas two others had high gamma-carboxylase activity and mRNA expression. The concentration of FLEEL at half-maximal velocity was normal in all the tumors examined (Groups I and II), and a relation was found between the level of expression of gamma-carboxylase and the maximal velocity for FLEEL carboxylation in the tumors in Group II (r = 0.98; P < 0.01). The microsomal content of normal prothrombin was within normal limits in all tumors (Groups I and II). CONCLUSIONS: Tumor vitamin K content has a critical role in the synthesis of des-gamma-carboxy prothrombin. Furthermore, the gamma-carboxylase defect, which is observed in some secreting tumors, is the result of the defective gene expression of a normal enzyme and not the consequence of the presence of a competitive inhibitor. It is possible that a 75% reduction in gamma-carboxylase gene expression could take a part in the secretion of des-gamma-carboxy prothrombin, but this mechanism is not predominant.

Biomarkers↗
PubMed1994

Accumulation of pefloxacin in the lower respiratory tract demonstrated by bronchoalveolar lavage.

The in-vivo pulmonary disposition of pefloxacin in alveolar macrophages alveolar macrophages and in the alveolar epithelial lining fluid recovered by bronchoalveolar lavage was studied in 10 healthy volunteers. Bronchoalveolar lavage was performed either 2 or 4 h after oral intake of 800 mg of the drug. The recovered fluid was immediately centrifuged and processed for the assays. Pefloxacin was assayed by High Pressure Liquid Chromatography (HPLC) and by a microbiological method. The mean concentrations of pefloxacin assayed by HPLC were 106 +/- 11.1 mg/L in alveolar macrophages and 88.2 +/- 10 mg/L in the epithelial lining fluid, whereas the mean serum concentration was 6.67 +/- 0.47 mg/L. Therefore, pefloxacin accumulated rapidly in human alveolar macrophages. The high epithelial lining fluid concentrations may be attributed to lipophilicity of the drug and to rapid diffusion from blood, pulmonary cells and interstitium during the bronchoalveolar lavage procedure. The substantial accumulation of pefloxacin in alveolar components (alveolar macrophages and epithelial lining fluid) endorses its use in the treatment of intracellular bacterial infections such as legionellosis; for these diseases, pefloxacin represents an alternative to the macrolide antibiotics.

Adult↗
PubMed1994

Cytokine modulation of basophil histamine release in wasp-venom allergy.

We report the effect of interleukin-3 (IL-3) and of other cytokines on antigen-induced basophil histamine release in wasp-venom-allergic subjects. Leukocytes from 12 patients with documented anaphylactic sensitivity to wasp venom were preincubated in the presence or absence of IL-3, granulocyte/macrophage-colony stimulating factor (GM-CSF), IL-5, IL-8, or stem cell factor (SCF). Washed cells were then exposed to venom and to other secretagogues, and histamine release in the supernatant was measured fluorometrically. Preincubation of leukocytes with IL-3, GM-CSF, or IL-5 (0.02-2 ng/ml), but not with IL-8 and SCF, caused a dose-dependent enhancement of antigen-induced basophilic histamine release in all subjects tested. Mean maximum increase was about 100% for IL-3, IL-5, and GM-CSF. The priming effect of IL-3 was rapid, persisted up to 12 h, and was not accompanied by a change in cellular histamine. IL-3 had a comparable enhancing effect when basophils were triggered with anti-IgE or N-formylmethionylphenylalanine (FMP). By contrast, IL-3 had no effect on substance-P-induced histamine release. The significant enhancement of basophil releasability to antigen in wasp-venom allergy by very low concentrations of IL-3, GM-CSF, and IL-5 suggests that cytokines in the basophil (mast-cell?) microenvironment could be critical factors in determining the variability of sting reactions in Hymenoptera-venom-allergic subjects.

Adolescent↗
PubMed1994

[Updating of relative data on tocopherols in clinical biochemistry].

The working group on lipophilic vitamins of the FSBC has reviewed current knowledge in the field of tocopherols and tried to summarize the most important and recent aspects that may be useful to clinical practitioners. The molecular structure of tocopherols and tocotrienols, their biogenesis, their analysis in foods, their metabolism in humans, their measurement in biological fluids, and the organism's needs and dietary requirements are reviewed. Their main functions as antioxidants and free radical scavengers are described at the molecular, ultra-structural, cellular and organ levels. The interest of these vitamins in three pathologies in which oxidative-stress has been implicated (atherosclerosis, cancer, kidney failure) is discussed.

Arteriosclerosis↗
PubMed1993

Detection and measurement of vitamins K1 and K2 in human cortical and trabecular bone.

Vitamin K plays an essential role in the gamma carboxylation of the gla-containing proteins of bone matrix, such as osteocalcin. We have measured the concentration of vitamin K1 (VK) and of the menaquinones MK-6, MK-7, and MK-8, the three major vitamin K2 moieties, in trabecular and cortical bone taken from the femoral neck of patients undergoing hip replacement. Both bone compartments were found to contain large amounts of VK, MK-6, MK-7, and MK-8. Concentrations were as high as those reported for the liver, the major storage organ for vitamin K. Further research is required to examine the association between vitamin K in bone and the gamma carboxylation of vitamin K-dependent bone proteins.

Aged↗
PubMed1993

In-vitro concentration of azithromycin in human phagocytic cells.

The in-vitro intraphagocytic uptake and retention of azithromycin in both human polymorphonuclear leucocytes (PMN) and alveolar macrophages was measured by an improved high-performance liquid chromatography (HPLC) method that was approximately three-fold more sensitive than previous methods. Azithromycin was accumulated in PMN and alveolar macrophages (about 300-fold), with maximum uptake being obtained after incubation for 60 min. Azithromycin was eliminated only partially from the cells during the washing process, and was released slowly during re-incubation of phagocytic cells in antibiotic-free medium. This intracellular retention distinguishes azithromycin from most of the macrolides and quinolones which, in spite of high I/E ratios, are released rapidly from cells.

Azithromycin↗