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Biomedical subjects

A Legrand

Publications and source records attributed to A Legrand.

At least 37 records · Page 2Linked to original sources

[Validation of a triage scale: first step in patient admission and in emergency service models].

INTRODUCTION: At present, most emergency services handle the multitude of various demands in the same unity of place and by the same team of nurses aides, with direct consequences on the waiting time and in the handling of problems of varying degrees of importance. Our service examines other administrative models based on a triage of time and of orientation. METHODS AND RESULTS: In a prospective study on 679 patients, we have validated a triage tool inspired from the ICEM model (International Cooperation of Emergency Medicine) allowing patients to receive, while they wait, information and training, based on the resources provided, in order to deal with their particular medical problem. CONCLUSION: The validation of this tool was carried out in terms of its utilization as well as its reliability. It appears that, with the type of triage offered, there is a theoretical reserve of waiting time for the patients in which the urgency is relative, and which could be better used in the handling of more vital cases.

Adult↗

[COPD: spirometry in general medicine].

Chronic Obstructive Pulmonary Disease (COPD) is a major cause of chronic morbidity and mortality throughout the world. COPD typically develops for a number of years before seeking medical help. Early detection by primary care physicians is a unique opportunity to intervene when the disease is not yet a health problem. COPD is characterized by airflow limitation that is not fully reversible. Pulmonary function test is thus the cornerstone for the early diagnosis of this disease. Determination of two lung volumes is enough to detect airway obstruction by spirometry: the Force Expiratory Volume during the first second (FEV1) of expiration and the Vital Capacity. Unlike electrocardiography, the procedure is a key stage in the performance of a spirometry. However, with some precautions described in the present paper, the manoeuvre is easy to perform properly. Technical considerations and limitations are also described. The interpretation of the results obtained needs a good understanding of the "normal value" and of the definition of an obstructive defect. When an obstruction is demonstrated with this simple test, it must be completed by more advanced tests to confirm the nature of the obstruction. Among these tests, the bronchodilators challenge testing, the evaluation of hyperinflation by plethysmography and the diffusing capacity of the lungs are the most currently realised tests in pulmonary function laboratories. Early detection and accurate diagnosis are necessary steps to improve the management and prevention of COPD.

Family Practice↗

[The pneumology department].

The department of pneumology of the Erasme hospital exists since 25 years. The basic clinical activities include pulmonary function testing (7,500 patients per year), endoscopy, including interventional endoscopy (1,500 patients per year), thoracic oncology, allergology, rehabilitation and aid to smoking cessation. The following expertise fields have been largely developed: lung transplantation, treatment of cystic fibrosis in collaboration with the children's hospital Reine Fabiola, occupational.

Belgium↗

Comparison of the effects of O2*-/HO* free radical- and copper ions-oxidized LDL or lipoprotein(a) on the endothelial cell releases of tissue plasminogen activator and plasminogen activator inhibitor-1.

We investigated the effects of low density-lipoproteins (LDL) and lipoprotein(a) [Lp(a)] oxidized by O2*-/HO* free radicals generated by gamma radiolysis of water, on the release of tissue Plasminogen Activator (tPA) and of its main inhibitor Plaminogen Activator Inhibitor-1 (PAI-1) by human umbilical vein endothelial cells (HUVEC). These effects were compared to those of lipoproteins issued from the same preparations but oxidized by the classical copper ions procedure. The results showed that O2*-/HO* free radical oxidized LDL and Lp(a) led to a dramatic decrease of PAI-1 release but did not affect tPA release, whereas copper oxidation of lipoproteins resulted in an increase in PAI-1 release and a decrease in tPA release. Chemical analysis revealed that O2*-/HO* free radical oxidized lipoproteins exhibited very much lower levels of phosphatidylcholine hydroperoxides, lysophosphatidylcholine and oxysterols (7-ketocholesterol, 7beta-hydroxycholesterol, 5,6beta-epoxycholesterol) than copper oxidized LDL. Thus, the discordant effects of O2*-/HO* oxidized and copper oxidized LDL and Lp(a) on the endothelial releases of PAI-1 and tPA appeared to be due to qualitatively and/or quantitatively different formation of oxidized components by the two oxidation processes.

Copper↗

Identification of an internal gene to the human Galectin-3 gene with two different overlapping reading frames that do not encode Galectin-3.

We previously reported that alternative transcripts were initiated within the second intron of the human Galectin-3 gene (LGALS3). We now demonstrate that these transcripts arise from an internal gene embedded within LGALS3 and named galig (Galectin-3 internal gene). Tissue-specific expression of galig was assayed by screening of several human tissues. Contrary to LGALS3, galig appears to be tightly regulated and principally activated in leukocytes from peripheral blood. Cloning and characterization of galig transcripts revealed that they contain two out-of-frame overlapping open-reading frames (ORFs). Transfection of expression vectors encoding enhanced green fluorescent protein (EGFP) chimeras indicated that both ORFs could be translated in proteins unrelated to Galectin-3. The ORF1 polypeptide targets EGFP to cytosol and nucleus whereas ORF2 targets EGFP to mitochondria. These results revealed the exceptional genetic organization of the LGALS3 locus.

Amino Acid Sequence↗

Respiratory effects of the external and internal intercostal muscles in humans.

The current conventional view of intercostal muscle actions is based on the theory of Hamberger (1749) and maintains that as a result of the orientation of the muscle fibres, the external intercostals have an inspiratory action on the lung and the internal interosseous intercostals have an expiratory action. Recent studies in dogs, however, have shown that this notion is only approximate. In the present studies, the respiratory actions of the human external and internal intercostal muscles were evaluated by applying the Maxwell reciprocity theorem. Thus the orientation of the muscle fibres relative to the ribs and the masses of the muscles were first assessed in cadavers. Five healthy individuals were then placed in a computed tomographic scanner to determine the geometry of the ribs and their precise transformation during passive inflation to total lung capacity. The fractional changes in length of lines with the orientation of the muscle fibres were then computed to obtain the mechanical advantages of the muscles. These values were finally multiplied by muscle mass and maximum active stress (3.0 kg cm-2) to evaluate the potential effects of the muscles on the lung. The external intercostal in the dorsal half of the second interspace was found to have a large inspiratory effect. However, this effect decreases rapidly in the caudal direction, in particular in the ventral portion of the ribcage. As a result, it is reversed into an expiratory effect in the ventral half of the sixth and eighth interspaces. The internal intercostals in the ventral half of the sixth and eighth interspaces have a large expiratory effect, but this effect decreases dorsally and cranially. The total pressure generated by all the external intercostals during a maximum contraction would be -15 cmH2O, and that generated by all the internal interosseous intercostals would be +40 cmH2O. These pressure changes are substantially greater than those induced by the parasternal intercostal and triangularis sterni muscles, respectively.

Adult↗

Plasma progesterone kinetics following surgical treatment of ectopic pregnancies.

OBJECTIVES: Comparative study of plasma progesterone and betaHCG kinetics following surgical treatment of ectopic pregnancy. STUDY DESIGN: Prospective study involving 62 patients with tubal ectopic pregnancies. Study of the kinetics of plasma progesterone and betaHCG, and the correlation coefficient between plasma progesterone and betaHCG levels during post-operative follow-up. RESULTS: Thirty-nine patients were treated by salpingostomy and 23 by salpingectomy. Analyzing the betaHCG kinetics according to treatment revealed that both curves were convergent on day 2. Progesterone kinetics differed greatly in that they appeared "parallel and confused". Analyzing the correlation between betaHCG and progesterone levels proved the absence of a significant link. CONCLUSIONS: Studying the kinetics of plasma progesterone after surgical treatment of ectopic pregnancies revealed a fast decrease in progesterone. Statistical analysis of the progesterone concentration showed that post-operative kinetics is fully independent from that of betaHCG. Progesterone therefore cannot be substituted to betaHCG for post-operative follow-up.

Chorionic Gonadotropin, beta Subunit, Human↗

Implication of acyl chain of diacylglycerols in activation of different isoforms of protein kinase C.

We synthesized diacylglycerols (DAGs) containing omega-6 or omega-3 polyunsaturated fatty acids [i.e., 1-stearoyl-2-arachidonoyl-sn-glycerol (SAG), 1-stearoyl-2-docosahexaenoyl-sn-glycerol (SDG), and 1-stearoyl-2-eicosapentaenoyl-sn-glycerol (SEG)] and assessed their efficiency on activation of conventional (alpha, beta I, gamma) and novel (epsilon, delta) protein kinase C (PKC). SAG exerted significantly higher stimulatory effects than SDG and SEG on activation of PKC alpha and PKC delta. Activation of PKC beta I by SEG and SDG was higher than that by SAG. Activation of PKC gamma did not differ significantly among DAG molecular species. Addition of SAG to assays containing SEG and SDG exerted additive effects on activation of alpha and epsilon, but not on beta I and gamma, isoforms of PKC. SDG- and SEG-induced activation of PKC delta was significantly curtailed by the addition of SAG. Three DAG species significantly curtailed the PMA-induced activation of beta Iota, gamma, and delta, but not of alpha and epsilon, isoforms of PKC. Our study demonstrates for the first time that in vitro activation of different PKC isoenzymes vary in response to different DAG species, and one can envisage that this differential regulation may be responsible for their in vivo effects on target organs.

Diglycerides↗

Heterogeneity of metabolic activity in the canine parasternal intercostals during breathing.

In the dog, the inspiratory mechanical advantage of the parasternal intercostals shows a marked spatial heterogeneity, whereas the expiratory mechanical advantage of the triangularis sterni is relatively uniform. The contribution of a particular respiratory muscle to lung volume expansion during breathing, however, depends both on the mechanical advantage of the muscle and on its neural input. To evaluate the distribution of neural input across the canine parasternal intercostals and triangularis sterni, we have examined the distribution of metabolic activity among these muscles in seven spontaneously breathing animals by measuring the uptake of the glucose tracer analog [(18)F]fluorodeoxyglucose (FDG). FDG uptake in any given parasternal intercostal was greatest in the medial bundles and decreased rapidly toward the costochondral junctions. In addition, FDG uptake in the medial parasternal bundles increased from the first to the second interspace, plateaued in the second through fifth interspaces, and then decreased progressively toward the eighth interspace. In contrast, uptake in the triangularis sterni showed no significant rostrocaudal gradient. These results overall strengthen the idea that the spatial distribution of neural input within a particular set of respiratory muscles is closely matched with the spatial distribution of mechanical advantage.

Animals↗

Standard treatment of alpha-tocopherol in Alagille patients with severe cholestasis is insufficient.

Alpha-tocopherol (alpha-T) is the most effective lipid-soluble antioxidant present in cells. We investigated the efficacy of alpha-T supplements for preventing lipid peroxidation in patients with Alagille syndrome, according to the severity of cholestasis. Patients were assigned to two groups on the basis of plasma bilirubin concentration (group I, bilirubin <100 microM; group II, bilirubin >100 microM). alpha-T concentrations were determined in plasma, in isolated lipoproteins, and in red blood cell membranes. In both groups of patients, alpha-T concentrations in plasma were similar to those in control subjects, but the distribution of alpha-T in lipoproteins was affected by the abnormal lipoprotein pattern in these patients. The efficacy of alpha-T was estimated by determining the amount of hydroperoxide produced from phosphatidylcholine and phosphatidylethanolamine (PE) molecular species owing to oxidative stress induced by lipoxygenase treatment. The concentrations of phosphatidylcholine molecular species and its corresponding hydroperoxides were significantly higher in both groups of patients. In group I, alpha-T and PE molecular species concentrations were similar to those in control subjects, but PE hydroperoxide concentrations were higher than those in the control subjects. In group II, alpha-T concentration was significantly lower and the concentrations of some PE molecular species and all PE hydroperoxides were lower than those in the control subjects. In conclusion, erythrocyte membrane alpha-T concentration was significantly lower only in patients with severe jaundice, despite alpha-T supplementation, raising the question as to whether the usual treatment was appropriate in this group.

Adolescent↗

In vitro study of the cytotoxicity of isolated oxidized lipid low-density lipoproteins fractions in human endothelial cells: relationship with the glutathione status and cell morphology.

Toxic effects of oxidized lipid compounds contained in oxidized LDL to endothelial cells are involved in the pathogenesis of atherosclerosis. Glutathione (GSH) plays an important role in the redox status of the cell and in the protective effect against oxidant injuries. However, little is known about the respective effect of these different oxidized lipid compounds toward cytotoxicity and GSH status of the cell. In this report, we isolated by high-performance liquid chromatography oxidized lipid compounds from low-density lipoproteins (LDL) oxidized by copper and we examined their effects on cultured endothelial cells. Cytotoxicity and GSH status were determined after incubation of endothelial cells with crude LDL or isolated lipid fractions derived from cholesterol, phospholipids, or cholesteryl esters. Their effects on cell morphology were also assessed. Oxidized lipids coming from cholesteryl esters (hydroperoxides or short-chain polar derivatives) induced a slight but significant GSH depletion without inducing cytotoxicity. The same species coming from phospholipids induced a more pronounced GSH depletion and a cytotoxic effect which is only present for the more polar compounds (short-chain polar derivatives) and corresponding to a total GSH depletion. In contrast, fractions containing oxysterols had a larger cytotoxic effect than their effect on GSH depletion suggesting that their cytotoxic effects are mediated by a GSH-independent pathway. All together, these data suggest that LDL-associated oxidized lipids present in copper-oxidized LDL exert cytotoxicity by an additional or synergistic effect on GSH depletion, but also by another mechanism independent of the redox status of the cell.

Cell Line↗

Immunocytochemical localization of the sigma(1) receptor in the adult rat central nervous system.

In order to characterize the localization of the sigma(1) receptor in the adult rat central nervous system, a polyclonal antibody was raised against a 20 amino acid peptide, corresponding to the fragment 143-162 of the cloned sigma(1) receptor protein. Throughout the rostrocaudal regions of the central nervous system extending from the olfactory bulb to the spinal cord, intense to moderate immunostaining was found to be associated with: (i) ependymocytes bordering the entire ventricular system, and (ii) neuron-like structures located within the parenchyma. Double fluorescence studies confirmed that, throughout the parenchyma, sigma(1) receptor-immunostaining was essentially associated with neuronal structures immunostained for the neuronal marker betaIII-tubulin. In all rats examined, high levels of immunostaining were always associated with neurons located within specific regions including the granular layer of the olfactory bulb, various hypothalamic nuclei, the septum, the central gray, motor nuclei of the hindbrain and the dorsal horn of the spinal cord. In contrast, only faint immunostaining was associated with neurons located in the caudate-putamen and the cerebellum. Electron microscope studies indicated that sigma(1) receptor immunostaining was mostly associated with neuronal perikarya and dendrites, where it was localized to the limiting plasma membrane, the membrane of mitochondria and of some cisternae of the endoplasmic reticulum. At the level of synaptic contacts, intense immunostaining was associated with postsynaptic structures including the postsynaptic thickening and some polymorphous vesicles, whereas the presynaptic axons were devoid of immunostaining. These data indicate that the sigma(1) receptor antibody prepared here, represents a promising tool for further investigating the role of sigma(1) receptors.

Animals↗

Characterization of the trabecular rat bone mineral: effect of ovariectomy and bisphosphonate treatment.

Bisphosphonates, potent inhibitors of bone resorption, have been used clinically to correct the continued loss of bone mass in osteoporosis and in other conditions. However, there has been some concern that long-term treatment with these compounds, as well as more recently developed drugs, may also decrease the rate of bone formation. Bisphosphonates, which are strongly bound to hydroxyapatite crystals, may alter the structure and reactivity of the crystals, interfere with new crystal nucleation and growth, as well as alter the short-range order of newly formed crystals. We have investigated the chemistry and structure of the solid calcium-phosphate mineral phase of lumbar vertebrae of ovariectomized, 6.5-month-old rats treated with bisphosphonates for 1 year after onset of osteopenia. Appropriate control groups were used for comparison. The techniques used to assess the mineral phase were chemical analyses, Fourier transform-infrared (FT-IR) and FT-Raman spectroscopy, FT-IR microspectroscopy, and phosphorus-31 magic-angle-sample spinning nuclear magnetic resonance spectroscopy ((31)P MAS NMR). The (31)P MAS NMR spectra of trabecular bone of lumbar vertebrae of control, ovariectomized, and treated animals were similar. However, there were several significant differences in the results obtained by FT-IR spectroscopy of the whole tissue samples, FT-IR microspectroscopy of sections of bone, and chemical analyses. For example, whereas chemical analyses demonstrated that the CO(3) content of the mineral phase of the ovariectomized animals was decreased compared with controls, FT-IR microspectroscopy of bone sections showed no changes in the relative CO(3) content, but some changes in the environment of the CO(3) groups. However, chemical analyses of the crystals, combined with data from all three spectroscopic methods and with data from serum analysis, did indicate small changes in the mineral phase after ovariectomy, corrected after treatment with bisphosphonates. In any event, the chemical and structural data in the present studies demonstrate that the bisphosphonate, tiludronate, does not significantly alter the mineral components of bone after 1 year of treatment during the course of which bone loss was reversed.

Animals↗

Is anhedonia a specific dimension in chronic schizophrenia?

This article explores the relationships among anhedonia, depression, and schizophrenic symptomatology in chronic schizophrenia. To explore these relationships, factor analysis methods were used to analyze the latent organization of the variables. The Fawcett Clark Pleasure Capacity Scale-Physical Pleasure (FCPCS-PP) and the abridged version of the Beck Depression Inventory (BDI) were completed by 150 subjects who met research diagnostic criteria for definite chronic schizophrenia. The schizophrenic symptomatology was rated using the Positive and Negative Syndrome Scale (PANSS). Two separate exploratory principal components analyses were completed, followed by varimax rotation. The first was made on the correlation matrix comprising items from both the FCPCS-PP and PANSS and yielded a five-factor solution with virtually no overlap of the significant factor loadings for the items from each scale. The second was made on the correlation matrix comprising items from both the FCPCS-PP and BDI and yielded a two-factor solution with virtually no overlap of the significant factor loadings for the items from each scale. Confirmatory factor analyses corresponding to the two exploratory factor analyses were done to examine the goodness of fit of the five-factor solution versus a four-factor solution and the two-factor solution versus a one-factor solution. The five-factor and the two-factor solutions yielded the best fit to the data relative to the other models tested. The findings support the view that part of anhedonia is a construct that is distinct and separate from depression and schizophrenic symptomatology in chronic schizophrenia.

Adult↗