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Biomedical subjects

J C Lefebvre

Publications and source records attributed to J C Lefebvre.

At least 37 records · Page 2Linked to original sources
PubMed1997

Self-efficacy for arthritis pain: relationship to perception of thermal laboratory pain stimuli.

OBJECTIVE: To examine how self-efficacy for arthritis pain relates to the perception of controlled laboratory pain stimuli. METHODS: Forty patients with osteoarthritis completed self-report measures of self-efficacy for arthritis pain. They then participated in a single experimental session in which measures of thermal pain threshold and tolerance were collected, as well as measures of the perceived intensity and unpleasantness of a range of thermal pain stimuli. RESULTS: Correlational analyses revealed that patients reporting high self-efficacy for arthritis pain rated the thermal pain stimuli as less unpleasant than those reporting low self-efficacy. When subjects scoring very high and very low in self-efficacy were compared, it was found that subjects scoring high on self-efficacy for arthritis pain had significantly higher pain thresholds and pain tolerance than those scoring low on self-efficacy. CONCLUSIONS: These results indicate that self-efficacy for arthritis pain is related to judgments of thermal pain stimuli. Implications for the understanding of arthritis pain and for future laboratory research are discussed.

Attitude to Health↗
PubMed1997

Pain coping strategies and coping efficacy in rheumatoid arthritis: a daily process analysis.

Data from daily diaries were used to analyze pain coping processes in rheumatoid arthritis patients. For 30 consecutive days, 53 individuals described the pain coping strategies they used that day and rated the efficacy of their coping, joint pain, and positive and negative mood. Relations among variables were examined across-persons and within-persons over time. At the across-persons level of analysis, (i) daily coping efficacy was unrelated to pain coping or pain intensity, and (ii) the more frequent daily use of a wide variety of pain coping strategies was correlated with greater pain. Within-person analyses provided unique information about the relations among coping, pain, and mood not apparent in the across-persons results. Specifically, these analyses showed that increases in daily coping efficacy were not only related to decreases in pain, but also to decreases in negative mood and increases in positive mood. Time-lagged effects of coping and coping efficacy were also found. Individuals who reported high levels of coping efficacy on one day had lower levels of pain on the subsequent day. The daily use of pain reduction efforts and relaxation strategies also contributed to an improvement in next-day pain and an enhancement of positive mood. The implications of these findings for the assessment of pain and coping in rheumatoid arthritis patients are discussed.

Adaptation, Psychological↗
PubMed1997

Altered sialylation of alveolar macrophages in HIV-1-infected individuals.

In previous studies, we have demonstrated that O-glycans at the surface of HIV-1-infected cell lines were hyposialylated. Moreover, we and others have shown that HIV+ individuals produced autoantibodies that react with hyposialylated CD43, on T cell lines. Since the autoantigen responsible for this abnormal immune response was not easily found in the peripheral blood cells of corresponding patients, we searched for its possible presence in other sites. Using fluorescence staining of alveolar macrophages with various lectins, we show that the binding of the PNA lectin specific for asialo O-glycans is much more efficient on cells from HIV-1-infected individuals. Moreover, the degree of reactivity of PNA is correlated with the clinical stage of the illness.

Adult↗
PubMed1996

Alteration of CD44 expression in HIV type 1-infected T cell lines.

CD44 is known to interfere in HIV replication and to participate in many physiological processes such as lymphocyte binding to high endothelial venules of lymphoid tissue, lymph nodes, and mucosal endothelium. The T cell lines MOLT-4 and CEM, and CEM subclones were infected with the HIV-1 LAI strain and monitored for the expression of CD44 during the course of chronic virus production until the infected cells were at the stage of latent infection. The levels of CD44 protein expression were quantified using cell surface immunostaining and biotinylation. The maturation of CD44 molecules was evaluated by metabolic sulforadiolabeling and CD44 mRNA was visualized by Northern blot analysis. We show a downmodulation of CD44 expression in infected T cell lines and subclones. This phenomenon was most evident at the stage of latent infection. Then, CD44 molecules were undetectable at both the protein and mRNA levels in latently infected CEM cells and CEM subclones. In addition, the 97-kDa standard CD44 isoform showed a shift upward, while detectable during the stage of chronic virus production. In latently infected MOLT-4 cells, the CD44 protein levels were dramatically decreased; CD44 mRNA was detected, but the sizes differed from the mRNA in uninfected cells. Since CD44 is known to regulate in part lymphocyte homing and HIV replication, the alterations that were observed in the expression of this molecule could interfere with the particular homing of HIV-infected cells and/or viral latency.

Alternative Splicing↗
PubMed1996

Pain coping strategies in children with juvenile primary fibromyalgia syndrome: correlation with pain, physical function, and psychological distress.

OBJECTIVES: The purpose of this study was twofold: 1) to describe the coping strategies used by children with juvenile primary fibromyalgia syndrome (JPFS), and 2) to examine how pain coping relates to measures of pain, disability/function, psychological distress, and pain behavior. METHODS: Sixteen children with JPFS completed the Child Version of the Coping Strategies Questionnaire (CSQ-C), the visual analog scale for pain, the McGill Pain Questionnaire, the Fibromyalgia Impact Questionnaire modified for children, the Arthritis Impact Measurement Scales 2, and the Symptom Checklist-90-Revised. Subjects also also underwent pain behavior observation. Pearson's product moment correlations were conducted to examine the relationship of coping to measures of pain and disability. RESULTS: The Pain Control and Rational Thinking composite factor score on the CSQ-C correlated with measures of pain severity, functional disability, and psychological distress. Results supported the internal reliability of the CSQ-C in assessing pain coping. CONCLUSIONS: These results suggest that the CSQ-C may provide a reliable measure for assessing variations in pain coping in JPFS patients. Behavioral interventions aimed at increasing the perception of pain control may be beneficial in treating JPFS.

Activities of Daily Living↗
PubMed1996

Pain in young adults--III: Relationships of three pain-coping measures to pain and activity interference.

The study had two purposes: (a) to examine the relationships among coping strategies measured by the Coping Strategies Questionnaire (CSQ) (1), the Vanderbilt Pain Management Inventory (VPMI) (2), and the Ways of Coping Inventory (WOC) (3) and identify the higher-order composite factors representing these relationships; and (b) to determine the degree to which individual coping scale scores and composite coping factor scores could explain variability in the pain intensity and pain-related activity interference reported by young adults. Measures of pain coping were collected from 206 young adults using the CSQ, VPMI, and WOC, along with measures of pain intensity, pain location, and the extent to which pain interfered with daily activities. Results indicated considerable variability in the reported frequency of use of pain-coping strategies and in pain intensity, location, and activity interference. Principal components factor analysis identified three higher-order coping factors (Emotional and Other-Directed Coping, Active Cognitive Coping, and Self-Efficacy for Pain Control) that explained 87% of the variance in individual coping scale scores. The degree to which individual scale scores and composite factor scores explained variability in pain intensity and activity interference variables was determined through a series of multiple regression analyses. The results revealed that individual scale scores, particularly the CSQ scales of catastrophizing and praying or hoping, were best able to explain the variance in measures of pain and activity interference. Taken together, these findings provide further support for the importance of coping variables in explaining the experience of pain and adjustment in young adults.

Adaptation, Psychological↗
PubMed1995

Autoantibodies directed against CD43 molecules with an altered glycosylation status on human immunodeficiency virus type 1 (HIV-1)-infected CEM cells are found in all HIV-1+ individuals.

Autoantibodies to lymphocytes have been detected in sera from human immunodeficiency virus type 1 (HIV-1)-infected individuals, and several autoantigens have been described. Among them, hyposialylated CD43 has been shown to be a target for autoantibodies in up to 47% of HIV+ individuals. However, the corresponding autoantigen (ie, the incompletely sialylated CD43) has not been isolated from blood cells of HIV-1-infected individuals. Recently, we have observed in vitro that HIV-1 productively or latently infected CEM cells (CEMLAI/NP) express CD43 molecules with modified glycosylation (mogly CD43). Using CEMLAI/NP cells, which do not express any structural viral antigen, we show now that all of the tested HIV+ sera from asymptomatic individuals, and up to 86% of those from subjects at the acquired immunodeficiency syndrome stage contain antibodies (mainly IgM and, to a lesser degree, IgG) that recognize the surface of CEMLAI/NP cells, and precipitate mogly CD43 molecules from the cells lysates. Taken together with our previous demonstration of altered glycosylation of CD43 from HIV-1-infected CEM cells in vitro, the constant antimogly CD43 autoimmune response observed from asymptomatic HIV-1+ subjects is likely to illustrate the occurrence of an altered glycosylation in vivo of the major lymphocyte surface CD43 glycoprotein, associated with HIV-1 infection.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Protection of a T-cell line from human immunodeficiency virus replication by the stable expression of a short antisense RNA sequence carried by a shuttle RNA molecule.

Adenovirus VA1 gene is efficiently transcribed by RNA polymerase III and gives rise to a small highly ordered RNA. To inhibit replication of human immunodeficiency virus (HIV), a chimeric VA1 RNA molecule was designed that contained a short antisense RNA sequence complementary to a conserved region of the HIV-1 rev encoding mRNA (28 nucleotides). This sequence, which was inserted into a projecting loop of the VA1 RNA central domain, was mainly single stranded and available for binding with its complementary sequence. The chimeric VA1 antisense was abundantly expressed in human cells constituting 3% of mRNA and promoted strong and specific inhibition of HIV-1 gene replication. The stable expression of antisense RNA in human T cells (CEM) protected these cells from HIV-1 multiplication for at least 3 months. No side effects were detected because of the lack of antisense effect upon replication of the closely related HIV-2. The VA1 gene may provide a suitably compact gene cassette for the intracellular expression of short antisense RNA directed against HIV.

Adenoviridae↗
PubMed1995

Induction by human immunodeficiency viruses types 1 and 2 of degradation of CD4 but not of a CD4 mutant unable to bind viral envelope glycoproteins.

HIV-1 appears to use a multiple gene strategy to regulate CD4 receptor expression, which emphasizes the importance of this regulation in the viral life cycle. The cytoplasmic interaction between gp160 and CD4 is probably the major event governing CD4 down-regulation, although other viral proteins, such as Nef (CD4 cell surface localization) and Vpu (CD4 degradation), are thought to participate as well. Because of the lack of vpu in HIV-2, we investigated the effects of two HIV-2 isolates (ROD 10 and EHO) on CD4 expression in the CEM T-cell line. We found that these HIV-2 strains induce CD4 degradation to a similar extent as that induced by an HIV-1 isolate (BRU). To assess the role of each viral protein involved in CD4 regulation (gp, Nef and Vpu), we developed cell lines expressing a mutated form of CD4 unable to efficiently bind gp160, in addition to their endogenous CD4. Using this system, we provide evidence that the mutated CD4 is always expressed in HIV-1-, and HIV-2-infected cells, independent of the presence of Nef, while the endogenous CD4 is completely lost. These results highlight the key role of intracytoplasmic gp-CD4 interaction, explaining in vitro the CD4 down-regulation in T-cell lines.

Base Sequence↗
PubMed1995

Lymphocytic CD43 and CD45 bear sulfate residues potentially implicated in cell to cell interactions.

CD43 is a major heavily glycosylated lymphocyte surface molecule. It has been shown to play an important role in lymphocyte activation and cell-cell interactions. Here we demonstrate that in human activated lymphocytes and CEM T cells, CD43 is a sulfated molecule. We also observed that CD45, another lymphocyte surface glycoprotein, is a sulfated molecule. 35SO4(2-) incorporation would thus appear to be an appropriate labeling method for CD43 and CD45 visualization. Moreover, we show that the level of cell surface protein sulfation can modulate CD43-mediated homotypic aggregation induced by CD43 monoclonal antibodies. It is well known that glycoprotein sulfation is required for various recognition phenomena. Since there are numerous potential sulfation sites on CD43 and CD45, these residues could play an important role in regulating cell-cell interactions.

Antibodies, Monoclonal↗
PubMed1995

Pain in young adults. II: The use and perceived effectiveness of pain-coping strategies.

OBJECTIVE: The first goal of the study was to determine the internal reliability of the Coping Strategies Questionnaire (CSQ) in young adults. The second goal was to examine the relation of the CSQ to reported pain levels. The third goal was to investigate the relationship between the CSQ and concomitant pain problems. The fourth goal was to compare young adults and different chronic pain samples in terms of the frequency of coping strategy use and perceived effectiveness of coping strategies. DESIGN: The study included 252 undergraduate students who were given the CSQ, a demographic and pain level questionnaire, and a concomitant pain problem survey. RESULTS: The results indicated that the CSQ was internally reliable when used to assess pain coping strategy use among young adults. Catastrophizing was found to be associated with both pain level and concomitant pain problems, with subjects reporting higher levels of catastrophizing having higher levels of pain and a higher frequency of both migraine headaches and low back pain. Finally, differences were found when comparing the perceived effectiveness in controlling and decreasing pain, and in the use of specific coping strategies in the young adult and chronic pain samples. The young adult sample reported a greater perceived efficacy in controlling and decreasing pain, compared to a sample of low back pain patients and a sample of myofacial pain patients. CONCLUSIONS: The results indicate that the CSQ is a reliable measure for the study of pain-coping strategies used in this population, and one that relates to differences reported in the experience of pain.

Adaptation, Psychological↗
PubMed1994

Altered glycosylation of leukosialin, CD43, in HIV-1-infected cells of the CEM line.

CD43 (leukosialin, gpL115, sialophorin) is a major sialoglycoprotein widely expressed on hematopoietic cells that is defective in the congenital immunodeficiency Wiskott-Aldrich syndrome. It is thought to play an important role in cell-cell interactions and to be a costimulatory molecule for T lymphocyte activation. Using a metabolic 35SO4(2-) radiolabeling assay or biotinylation of cell surface proteins, we describe here that CD43 are sulfated molecules the glycosylation of which is altered in human immunodeficiency virus type 1 (HIV-1)-infected leukemic T cells of the CEM line. Hyposialylation of O-glycans and changed substitution on N-acetylgalactosamine residues are observed. The glycosylation defect is associated with an impairment of CD43-mediated homotypic aggregation which can be restored by resialylation. The hyposialylation of CD43 on HIV-1+ cells may explain the high prevalence of autoantibodies directed against nonsialylated CD43 that have been detected in HIV-1-infected individuals. A defect in glycosylation of important molecules such as CD43 or, as we recently described, CD45 may explain alterations of T cell functions and viability in HIV-1-infected individuals. In addition, a possible implication of hyposialylation in the HIV-1-infected cells entrapment in lymph nodes could be envisioned.

Antibodies, Monoclonal↗
PubMed1994

Altered sialylation of CD45 in HIV-1-infected T lymphocytes.

Immunodeficiency caused by HIV infection probably results from profound dysregulation of normal T lymphocyte properties by the virus. Despite description of the virus cytopathicity and numerous modifications in T cell functions, such as perturbation of antigen receptor signaling, CD4 downregulation, and induction of apoptosis, the precise mechanisms underlying the disruption of normal immune responses have not yet been elucidated. In the present study, we show that HIV-1-infected lymphocytes of the CEM cell line (either latent or virus-producing) and HIV-1-infected CD4+ lymphocytes have several membrane proteins with altered glycosylation patterns. Using lectins with specificity for different carbohydrate moieties, we could demonstrate the presence of two exposed nonsialylated disaccharides: a terminal Gal beta 1-->3GalNAc and a terminal Gal beta 1-->4GlcNAc. In particular, CD45, one of the major T cell glycoproteins, appeared to be partially sialylated on N- and O-linked carbohydrate moieties. Concerning the latter, PNA lectin which recognizes nonsialylated terminal Gal beta 1-->3GalNAc might precipitate up to 75% of the total tyrosine phosphatase activity displayed by CD45 molecules from one latently HIV-1-infected CEM cell line. Since CD45 glycoproteins are thought to play an important regulatory role in cell-to-cell interactions owing to their variable extracellular region and because they may regulate membrane signaling through their intracellular phosphatase domains, we suggest that these altered CD45 molecules may present an abnormal signal for natural ligands such as the B-cell-specific surface receptor CD22, thus perturbing the normal immune response in HIV-1-infected individuals.

Carbohydrate Sequence↗
PubMed1994

Pain in young adults: I. Relationship to gender and family pain history.

OBJECTIVES/DESIGN: Two studies were carried out to examine how gender and family pain history related to pain and activity interference in young adults. The first study (n = 252 college students) examined how gender and family pain history related to pain intensity and the second study (n = 206 college students) examined how these variables related to pain intensity, location, and activity interference. Whenever possible, data from the two studies were combined for purposes of data analyses. RESULTS: Results indicated that more than half of the young adults studied reported experiencing some type of pain at the time of the investigation. The intensity of the pain was in the low range and the most frequent sites of pain were in the head and legs or feet. Gender differences were noted, with women reporting a greater number of sites of pain. Family pain history was found to be related to pain and activity interference. Subjects who had a strong family history of pain problems reported a greater number of pain sites, and higher levels of pain-related activity interference. CONCLUSIONS: Generalizability of results is limited due to the group of young adults studied, yet several conclusions relative to this group may be suggested. First, this group of young adults do appear to experience pain. Second, there may be gender differences in the types of pain they report and the ways they react to pain. Third, family history of pain may be related to the pain experiences of this group of young adults.

Activities of Daily Living↗
PubMed1990

Dermatomyositis-like syndrome in X-linked hypogammaglobulinemia. Case-report and review of the literature.

A case of dermatomyositis-like syndrome is described in a 19-year-old man with a history of Bruton's hypogammaglobulinemia. Although the patient had central-nervous-system manifestations (seizures), no echovirus was isolated in the cerebrospinal fluid, in contrast to previously reported cases. Data for our case and the 15 cases previously reported in the literature are reviewed. HLA typing of our patient revealed the presence of HLA B8 and DR3, which seems to play a major role in juvenile dermatomyositis.

Adult↗
PubMed1988

[Urinary Corynebacterium group D2 infections. A hospital epidemic and antibiotic sensitivity].

An outbreak of Corynebacterium group D2 urinary tract infections was recently observed at Nice CHR. These infections were characterized by alkaline urine. The five first cases were reported in the same department and the ten other cases were latter observed in different departments. Age average was 79 and all patients had either an intra-vesical catheter of a urinary collector. Among samples of material tested, only one gave a positive culture. The 15 isolates showed a similar identification and antibiotic phenotype. These strains presented a multiple antibiotic resistance: resistance to beta-lactams, aminoglycosides (except streptomycin), erythromycin, chloramphenicol, tetracyclines. All strains were susceptible to rifampin, pristinamycin, fusidic acid and vancomycin.

Aged↗