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[Old age and joint disease].

The seriousness of articular diseases in old persons is related to the loss of function and the rapid way this can lead to them being bed ridden. Rheumatoid polyarthritis is often difficult to distinguish from rhizomelic pseudopolyarthritis, these two diseases resemble each other at this age with the asthenia and loss of general health, the inflammatory pains which are peripheral and of nerve root origin. Among the metabolic arthropathies, articular chondrocalcinosis is frequent, and often latent, but sometimes it is destructive in particular in the hips and knees; septic arthritis today mainly occurs in the elderly, and the algoneurodystrophies are more frequent in old persons than in young subjects, following trauma or a hemiplegia. Arthrosis is obviously the main articular disease of senescence especially involving the joints of the lower limb, hip disease being less incapacitating than knee disease where surgical treatment is less often considered. The arthroses of the upper limbs especially of the shoulder are well tolerated. Osteochondromatosis, osteonecrosis of the internal condyle of the knee, the rapidly destructive arthropathies and hemarthrosis can develop as a complication of a simple arthrosis. In the spine vertebral hyperostosis is especially a disease of the elderly, it can occur alone or with an arthrosis of the posterior vertebral joints, a narrow spinal canal straight or narrowed. Medical treatment, physiotherapy, and finally surgery can give very satisfactory results in an old patient, avoiding loss of function, a miserable existence and becoming bed ridden.

Aged↗

Epstein-Barr virus-associated lymphoproliferative disease during methotrexate therapy for psoriasis.

BACKGROUND: Epstein-Barr virus (EBV)-associated lymphoproliferative disorders have recently been observed during treatment of rheumatoid arthritis and dermatomyositis with low-dose methotrexate. OBSERVATION: A patient with psoriasis developed a B-cell lymphoproliferative disorder during long-term treatment with low-dose methotrexate. The lymphoid cells expressed EBV latent membrane protein 1, and the EBV viral genome was present as demonstrated by in situ hybridization. Evaluation for EBV clonality showed that the lymph node contained clonal EBV DNA. Polymerase chain reaction studies confirmed that the B-cell lymphoproliferative disorder was mainly monoclonal, suggesting that the disorder arose from a single EBV-infected B-cell clone. CONCLUSIONS: Lymphoproliferative disorders associated with Epstein-Barr virus in which the clinicopathological presentation is similar to those occurring in patients after transplantation may be observed in patients with psoriasis treated with methotrexate. While it is impossible to rule out a fortuitous occurrence of an EBV-associated lymphoproliferative disorder and psoriasis treated with methotrexate in the same patient, EBV appears to be critical in the pathogenesis of the lymphoproliferative disorder in this patient.

Antigens, Viral↗

Competing-risk analysis of leukemia and nonleukemia mortality in X-irradiated, male RF mice.

The theory of competing risks, extended by the addition of several newly defined estimators, was applied to the analysis of mortality data for acutely X-irradiated, male RF mice, in which the cause of each death was assigned to one of four categories: myeloid leukemia (M), thymic lymphoma (T), lymphosarcoma and reticulum cell sarcoma (L), and all remaining causes (R), Doses from 0 to 450 rads were delivered within two age ranges: A) 5-6 weeks and B) 9-10 weeks, to give 11 treatment groups totaling 2,073 mice. The data were analyzed in terms of: 1) the nonparametric, Kaplan-Meier (K-M) adjusted survival function; 2) its logarithmic transform, the cumulative force of mortality (cumFM) function; 3) a disease model called "early terminating," applied to causes M and T; and 4) a "late-terminating" model, applied to causes L and R. For any given cause and group, two estimators were used, which measured, respectively: a) the relative lateness of the corrected (or adjusted) time course and b) the relative corrected incidence. For causes M and T, these were: a) the mean age of the force of mortality distribution (MAF), or corrected mean latent period; and b) the final cumFM. For causes L and R, the estimators were: a) the adjusted mean age at death (adjMAD), given an upper limit (as %) of adjusted mortality (adjMAD, 50% for L; adjMAD, 100%--the K-M estimator--for R) and b) the cumFM at a cutoff time of 640 days. For causes M and T, the MAF values showed highly significant decreases of the latent periods with dose, through 300 rads. The final cumFM data showed a marked increase of corrected incidence with dose, for both M and T. In addition, the data for cause M were consistent with a three-parameter, leukemogenic cell model that incorporated two opposing radiation effects: leukemogenic cell potentiation and cell killing. For cause R, the adjMAD, 100% data showed a general decrease with dose and considerable scatter. For cause L, the adjMAD, 50% values showed: for treatment A, a gradual decrease with dose through 300 rads; for treatment B, a highly significant drop for 150 rads, with little change for higher doses. The cumFM, 640-day values for both L and R showed a general increase of corrected incidence with dose. The mortality curves for all causes combined showed the expected life shortening, i.e., decreases of the mean age at death with dose, in the 0- to 300-rad range. In addition, the standard deviations of the mortality curves were significantly less for animals irradiated at age range B than at age range A, for each of the doses--150, 300, and 450 rads.

Animals↗

High incidence of monoclonal EBV episomes in Hodgkin's disease and anaplastic large-cell KI-1-positive lymphomas in HIV-1-positive patients.

A series of selected lymphoid malignancies (LMs) occurring in Italian HIV-1-infected (HIV+) patients, principally intravenous drug users, was investigated. In addition to small non-cleaved-cell (SNCC) and large-cell immunoblastic (LCI) non-Hodgkin's lymphomas (NHLs), a relatively high occurrence of anaplastic large-cell Ki-I-positive (ALC Ki-I+) lymphomas and Hodgkin's disease (HD) was observed, at variance with other reported series of HIV+ patients. Combined results of in situ hybridization and Southern-blot analyses, in conjunction with immunohistochemical detection of Epstein-Barr virus (EBV)-encoded latent membrane protein-I (LMP-I), showed an almost complete association of ALC Ki-I+ lymphomas and HD cases with EBV. The neoplastic cells of both these LMs also showed common immunophenotypic features such as frequent absence of B- and T-cell differentiation markers and expression of the Ki-I activation marker, while SNCC and LCI lymphomas were mainly of mature B-cell origin and Ki-I-. The concomitant high incidence of ALC Ki-I+ lymphomas and HD in a specific group of HIV+ patients, their almost complete association with EBV in clonal and episomal form and the great similarity in differentiation, activation and virological markers which they display suggest that these LMs are pathological variants of a continuous spectrum of HIV-I-associated disorders etiopathologically linked to EBV.

Antigens, CD↗

Epstein-Barr virus strain type and latent membrane protein 1 gene deletions in lymphomas in patients with rheumatic diseases.

OBJECTIVE: Recent studies have shown that immunomodulatory therapy for the treatment of rheumatic diseases can be associated with the development of Epstein-Barr virus (EBV)-associated lymphoproliferative disorders. The present study was undertaken to determine the strain type of EBV in lymphoproliferative disorders that occur in patients with rheumatic disease and to investigate EBV latent membrane protein 1 (LMP-1) gene deletions that occur in these lymphoproliferative disorders. METHODS: Ten EBV-associated lymphoid neoplasms in patients with rheumatoid arthritis or dermatomyositis were analyzed by polymerase chain reaction to determine EBV strain type and to investigate for the presence of a previously characterized 30-basepair deletion in the LMP-1 gene. RESULTS: The results indicated that lymphoproliferative disorders in these patients can harbor EBV strain type A or B, with a predominance of type A infection (80%). It was also shown that both wild-type and mutated LMP-1 genes can be found in these neoplasms, with the deleted form of the LMP-1 gene occurring in one-third of cases in this series. CONCLUSION: LMP-1 deletions associated with certain aggressive lymphoid neoplasms are not required for the genesis of lymphoproliferative disorders in patients with rheumatic disease. The relative frequencies of type A and type B EBV strains in these lymphoproliferative disorders show similarities to the frequencies in patients with post-solid organ transplantation immunosuppression-associated lymphoproliferative disorders.

Adolescent↗

[A case of progressive multifocal leukoencephalopathy presenting white matter MRI lesions extending over the cerebral cortex and a marked decrease in cerebral blood flow on SPECT, and associated with HTLV-I infection].

We report a 47-year-old woman with progressive multifocal leukoencephalopathy (PML). She was a carrier of HTLV-I virus, and developed subacute right hemiparesis and marked motor aphasia. She had a malignant lymphoma in the left neck and basal cell carcinoma in the right inguinal region. Three months after the onset, she became unable to walk because of the right leg weakness or to speak because of motor aphasia. Magnetic resonance imaging (MRI) revealed multifocal T2-high lesions in the white matter of the left frontal lobe, and a brain biopsy revealed demyelinating pathology. A biopsy of the left parotid gland revealed a diffuse pleomorphic type large B cell lymphoma. Although anti-HTLV-I antibody was positive in the serum and cerebrospinal fluid (CSF), no adult T-cell leukemia (ATL) cells were found in the blood or CSF. The patient was then admitted to our hospital. Neurological examinations revealed severe motor aphasia, mild sensory aphasia/cognitive impairment, right hemiplegia, mild right hemihypesthesia, limb-kinetic apraxia in the left hand, idiomotor apraxia, agraphia, perseveration, marked spasticity and brisk tendon reflex in four extremities, and positive bilateral pathological reflexes. MRI showed multifocal T2-high lesions mainly in the cerebral white matter, predominantly in the left hemisphere, and partly in the cerebral cortex. No gadolinium enhancement was found. In addition, 99mTcECD-SPECT showed a broad decrease in cerebral blood flow (CBF) in the cortex. Anti-HTLV-I antibody was positive but anti-HIV antibody was negative in serum. ATL cells were found in 1-3% of the peripheral white blood cells after admission. CSF examination revealed that the cell count (1/microl), protein level (24 mg/dl), and IgG index (0.4) were all normal. However, the myelin basic protein level (321 pg/ml; normal < 102) was increased, JC virus DNA was detected by PCR, and anti-HTLV-I antibody (x 8) was detected in CSF. The regulatory region of the JC virus DNA in the CSF was partly deleted; immunostaining with anti-JC virus protein antibodies revealed the existence of JC virus in biopsied brain specimens, and these findings were consistent with PML. Her symptoms such as motor aphasia, cognitive dysfunction and left hemiparesis were subacutely progressive, and she developed akinetic mutism two weeks after admission. Since the efficacy of cytosine arabinoside for PML has been reported, she was administered 80 mg/day of the drug for five days. After treatment, her communication function was mildly improved but the efficacy was transient. Since it has been reported that HTLV-I, as well as HIV, activates the JC virus promoter and its proliferation, the latent infection of HTLV-I in the central nervous system (CNS) in this case might have stimulated the JC virus proliferation, promoting lesion extension over the cerebral cortex. There have been only a few reports of broad decreases in CBF by SPECT in PML patients. Further MRI and SPECT studies on PML patients are therefore necessary to evaluate the significance of HTLV-I in promoting the JC virus infiltration into the CNS.

Aphasia, Broca↗

Baló's concentric sclerosis associated with primary human herpesvirus 6 infection.

BACKGROUND: Baló's concentric sclerosis (BCS) is a demyelinating disorder believed to be a rare variant of multiple sclerosis (MS). Human herpesvirus 6 (HHV-6) is a highly neurotropic virus causing severe central nervous system (CNS) infections predominantly following reactivation of latent HHV-6 in immunocompromised individuals. Primary infection with HHV-6 usually occurs in early childhood manifesting as exanthema subitum. The clinical spectrum of primary infection in adolescents or adults has not yet been evaluated. CASE REPORT: A previously healthy 13 year old girl developed acute hemianopsia and anomia 5 days after an episode of fever and malaise of unknown origin. Cerebral MRI revealed three white matter lesions, one with ring-like contrast enhancement. Lumbar puncture showed mononuclear pleocytosis of 30 cells/microl, oligoclonal IgG, and a normal protein level. Follow up cerebral MRI scans revealed lamellar concentric hemispheric lesions characteristic of BCS. The first neurological symptoms of the patient coincided with primary HHV-6 CNS infection, diagnosed by a positive PCR test of the CSF together with seroconversion. Response to antiviral and corticosteroid treatment was only temporary, but immunoglobulin treatment has so far been followed by clinical stability for 30 months. CONCLUSIONS: To our knowledge, this is the first report both of an association between HHV-6 and BCS and of immunoglobulin treatment of BCS. A late primary infection with HHV-6 might be associated with BCS. Further studies in patients with this rare disease are needed to confirm this association and to evaluate the efficacy of antiviral and immunoglobulin treatment.

Adolescent↗

Peripheral T-cell lymphoma complicated by a proliferation of large B cells.

We studied 14 cases that showed a morphologic appearance of peripheral T-cell lymphoma and contained substantial numbers of CD20+ large B cells. In all but 2 cases, the CD20+ large cells showed a mix of kappa and lambda light chain expression. Two cases showed a focal predominance of kappa expression. In situ hybridization using the EBER1 probe for detection of Epstein-Barr virus (EBV) RNA was performed on every case. EBV RNA was present in 10 cases. Of 8 cases with EBV RNA stained by immunohistochemistry for the latent membrane protein of EBV, 6 were positive. Double-labeling immunohistochemistry and in situ hybridization confirmed that EBV was present in the large B cells. Polymerase chain reaction (PCR) analysis showed a clonal rearrangement of the T-cell receptor (TCR)-gamma chain gene in 12 of 13 cases tested. One additional case showed a clonal rearrangement of the TCR-beta chain gene by Southern blot hybridization. PCR analysis showed a clonal immunoglobulin gene rearrangement in 5 cases, a suggestion of a clonal rearrangement in 1, an oligoclonal pattern in 4, and a polyclonal pattern in 4. The finding of large B and T cells may result in a misdiagnosis of a reactive process or of T-cell-rich B-cell lymphoma. The presence of EBV in some cases could cause further confusion with the reactive T- and B-immunoblastic proliferation of infectious mononucleosis.

Adult↗

Immunophenotypic and molecular analyses of acquired immune deficiency syndrome-related and Epstein-Barr virus-associated lymphomas: a comparative study.

Limited information is current available on the molecular and immunophenogenotypic characteristics of CD30-positive anaplastic large cell (ALC) lymphomas occurring in human immunodeficiency virus (HIV)-infected individuals. To address this issue, the authors have undertaken a combined analysis of these lymphomas in a comparison with other Epstein-Barr virus (EBV)-associated tumors in the setting of HIV infection. Twenty-one AIDS-related lymphomas, including five CD30-positive ALC and 11 small noncleaved cell (SNCC) lymphomas, and five Hodgkin's disease (HD) specimens were characterized regarding the immunophenogenotypic features, the frequency and subtype distribution of EBV (as defined by in situ hybridization [ISH], Southern blot, and a polymerase chain reaction [PCR] amplification of the EBV nuclear antigen-2 [EBNA-2] region) antigen expression (latent membrane protein-1 [LMP-1], EBNA-2, and for alterations of the tumor suppressor gene p53. Combined immunophenotypic and immunogenotypic analyses showed a derivation from anomalously matured B cells in four of five CD30-positive ALC lymphomas, whereas SNCC showed features of mature B cells; no evidence of immunoglobulin or TCR gene rearrangement could be obtained in HD cases. Combined ISH and Southern blot analyses revealed that EBV was more strictly associated with HD (five of five) and CD30-positive ALC lymphomas (four of five) than with SNCC lymphomas (four of 11). EBV-positive samples from CD30-positive ALC lymphomas carried type 1 EBV (two of two specimens tested), whereas both EBV subtypes were observed in SNCC lymphomas and HD samples. All three forms of viral latent gene expression were found in the EBV positive CD30-positive ALC lymphomas. SNCC specimens did not express LMP-1 or EBNA-2, whereas HD specimens expressed LMP-1 (four of five tested) but no EBNA-2. Immunostaining for ZEBRA was consistently negative. HHV-6 DNA sequences were detected by PCR in one SNCC of the 19 specimens analyzed. Three out of five CD30-positive ALC lymphoma specimens and six of 10 SNCC showed nuclear staining for p53. No mutation was detected in any of the three CD30-positive Alc lymphoma analyzed, whereas an aberrant SSCP pattern was found in all the four SNCC samples tested. At variance with SNCC lymphomas, AIDS-related B-cell CD30- positive ALC lymphomas are strictly associated with EBV infection and may also express the broad lymphoblastoid cell line-like (LMP-1-positive, EBNA-2-positive) pattern, and lack p53 genetic lesions. Unlike EBV, HHV-6 probably does not represent a relevant factor involved in the pathogenesis of CD30-positive ALC and other HIV related lymphomas.

Adult↗

Nasal T-cell lymphoma: a clinicopathologic entity associated with peculiar phenotype and with Epstein-Barr virus.

Recent evidence has shown that most nasal lymphomas (NL) are associated with a T-cell phenotype and are thus called nasal T-cell lymphomas (NTCL), but little information is available about the T-cell receptor (TCR) expression. The presence of Epstein-Barr virus (EBV) genome has been recently reported in NTCL in Oriental populations in which NL and EBV-associated tumors are more common and in occasional Occidental cases. This prompted us to investigate lymphoma biopsies from 7 non-Oriental patients with NTCL for the expression of natural killer (NK) and T-cell antigens, including TCR proteins, for the presence of EBV-encoded latent membrane protein (LMP) using immunohistochemistry and for the presence of EBV DNA and Epstein-Barr early region (EBER) RNA using in situ hybridization (ISH). Six cases displayed a CD3-, TCR alpha beta-, TCR gamma delta-, CD2+, CD7+, CD5-, CD4-, CD8-, CD56+ phenotype, suggesting that these tumors may be peripheral T-cell lymphomas (PTCL) with extensive loss of T-cell antigens and expression of the NK-cell (CD56) antigen or, alternatively, NK-cell neoplasias. The remaining case was a gamma delta PTCL, as shown by the CD3+, TCR gamma delta+ phenotype and the biallelic gamma and delta TCR gene rearrangements. Using ISH, EBER RNA transcripts were detected in tumor cells in all cases and EBV DNA was shown in the 6 tested cases. In all cases, tumor cells expressed LMP. These findings support the concept that NTCL constitute a distinct group of lymphomas that, in addition to their peculiar clinical features, exhibit an unusual TCR "silent" CD56+ or TCR gamma delta+ phenotype and harbor the EBV. In view of the LMP transforming potential, these data suggest that EBV may play a role in the pathogenesis of NTCL.

Adolescent↗

Deletion variants within the NF-kappaB activation domain of the LMP1 oncogene in acquired immunodeficiency syndrome-related large cell lymphomas, in prelymphomas and atypical lymphoproliferations.

The latent membrane protein 1 (LMP1) oncogene of Epstein Barr virus (EBV) is expressed in tumor cells of acquired immunodeficiency syndrome (AIDS) related lymphomas, HIV-negative, EBV-associated malignant lymphoproliferations, nasopharyngeal carcinoma, as well as in reactive immunoblasts of infectious mononucleosis. Naturally occurring LMP1 deletion variants (LMP1-del), characterized by clustered mutations and a distinct 30 base pair deletion within the carboxy terminal domain of LMP1, essential for maximal NF-kappaB stimulation, have been identified in the same conditions. These variants prevail in AIDS-related lymphomas, and are associated with clinically aggressive behaviour in HIV-negative lymphomas, and are frequent in prelymphomatous and reactive states. Functional studies showing a growth advantage of cells infected by these variants may explain the accumulation of LMP1-del in these entities. In the carboxy terminal NF-kappaB activation domain of LMP1, evidence of a hypervariable region close to the highly conserved 23 outermost amino acids essential for malignant transformation, may reflect the natural selection of growth promoting variants involved in signalling pathways. The prevalence of the same mutational pattern in AIDS-related lymphoma as well as in hyperplastic reactive states and prelymphomas supports the hypothesis that these variants confer a growth advantage manifested under impaired cellular immunity.

Amino Acid Sequence↗

Evidence for an intracellular pool of a migration inhibitory factor-associated, activation antigen of human mononuclear phagocytes, Mo3e.

Mo3e is a protease-sensitive Ag (p75,50) selectively expressed by human monocytic cells stimulated in vitro by exposure to various activating factors including PMA. Here, we report the existence of a large intracellular pool of Mo3e Ag in addition to that expressed on the surface of activated U-937 cells. As detected by quantitative immunofluorescence analysis, permeabilization of unstimulated and PMA-stimulated U-937 cells revealed a latent pool of Mo3e Ag that was 75-fold and 9-fold greater, respectively, than the magnitude of Mo3e Ag expressed on the surface. PMA stimulation not only induced an increase in the relative proportion of Mo3e antigen expressed on the surface membrane, but also stimulated a 1.8-fold increase in "total" Mo3e detectable in permeabilized cells. Trypsin treatment of intact PMA-stimulated U-937 cells eliminated surface Mo3e expression but had little measureable effect on the total Mo3e pool. Permeabilization also uncovered a sequestered compartment of Mo3e Ag in I-937 cells, a variant of U-937 that is surface Mo3e negative. Although the PMA-induced surface Mo3e expression of U-937 was abrogated by cycloheximide, the total pool of Mo3e detectable in permeabilized PMA-stimulated cells was only partially reduced; cycloheximide treatment caused no reduction in the intracellular Mo3e compartment of unstimulated U-937 cells. Detergent lysates of PMA-stimulated U-937 cells exhibited undiminished quantities (relative to untrypsinized cells) of p75 and p50 proteins immunoreactive with anti-Mo3e mAb as detected by Western blotting. This trypsin-sequestered intracellular Mo3e Ag may serve as a reservoir for the up-regulated surface expression of Mo3e that occurs as a result of mononuclear phagocyte activation.

Antibodies, Monoclonal↗

IL-10 cooperates with TNF-alpha to activate HIV-1 from latently and acutely infected cells of monocyte/macrophage lineage.

IL-10 is elevated in HIV-1-infected individuals and has been implicated in disease progression. In this study, we investigated the effects of IL-10 on the activation of HIV-1 from infected monocytes and macrophages. Although IL-10 alone did not induce HIV-1 replication, in the presence of TNF-alpha, IL-10 markedly enhanced virion production from a chronically infected promonocytic cell line (U1) and in acutely infected monocyte-derived macrophages. Neutralizing mAbs to IL-10 and TNF-alpha indicated that both cytokines were essential for the induction and were required to generate a synergistic increase in virus expression. The effects of the two cytokines were distinguishable functionally since pretreatment with TNF-alpha attenuated the cytokine cooperativity, while pretreatment with IL-10 potentiated their cooperativity, suggesting that IL-10 and TNF-alpha play different roles in the activation of virus. Northern blot analysis as well as Ab blocking and cytokine secretion studies indicated that the induction of either endogenous TNF-alpha or IL-10 was not involved in the cooperativity, nor was an up-regulation of TNF-alpha receptors. In combination with TNF-alpha, IL-10 stimulated activating protein-1 (AP-1) and nuclear factor (NF)-kappa B binding activities and cooperated to increase HIV-1 steady-state mRNA levels and enhance long terminal repeat-directed transcription through activation of the NF-kappa B binding sites, suggesting the IL-10 effect occurs at least in part at the transcriptional level. These results indicate that IL-10, in addition to down-regulating the cellular immune response to HIV-1, may also play a role in TNF-alpha-mediated activation of HIV-1 replication in the monocyte/macrophage lineage.

Base Sequence↗

Cryptococcus neoformans gene expression during murine macrophage infection.

The fungal pathogen Cryptococcus neoformans survives phagocytosis by macrophages and proliferates within, ultimately establishing latent infection as a facultative intracellular pathogen that can escape macrophage control to cause disseminated disease. This process is hypothesized to be important for C. neoformans pathogenesis; however, it is poorly understood how C. neoformans adapts to and overcomes the hostile intracellular environment of the macrophage. Using DNA microarray technology, we have investigated the transcriptional response of C. neoformans to phagocytosis by murine macrophages. The expression profiles of several genes were verified using quantitative reverse transcription-PCR and a green fluorescent protein reporter strain. Multiple membrane transporters for hexoses, amino acids, and iron were up-regulated, as well as genes involved in responses to oxidative stress. Genes involved in autophagy, peroxisome function, and lipid metabolism were also induced. Interestingly, almost the entire mating type locus displayed increased expression 24 h after internalization, suggesting an intrinsic connection between infection and the MAT locus. Genes in the Gpa1-cyclic AMP-protein kinase A pathway were also up-regulated. Both gpa1 and pka1 mutants were found to be compromised in macrophage infection, confirming the important role of this virulence pathway. A large proportion of the repressed genes are involved in ribosome-related functions, rRNA processing, and translation initiation/elongation, implicating a reduction in translation as a central response to phagocytosis. In summary, this gene expression profile allows us to interpret the adaptation of C. neoformans to the intracellular infection process and informs the search for genes encoding novel virulence attributes.

Animals↗

Molecular pathogenesis of Epstein-Barr virus associated posttransplant lymphomas: new insights through latent membrane protein 1 fingerprinting.

BACKGROUND: Fingerprint amino acid patterns within the carboxy terminus of the latent membrane protein (LMP1) oncoprotein of Epstein-Barr virus (EBV) allow individual strain identification at the molecular level. LMP1 is expressed in the tumor cells of EBV-associated posttransplant lymphomas (PTLs) and the LMP1 genome is also identified in lymphocytes of most donors of allogeneic bone marrow. Therefore, LMP1 genotyping in donor lymphocytes and PTL tumor cells, together with sex chromatin determination of tumor cells, allows to determine the origin of PTL tumor cells and the origin of individual EBV strains harboured by them. METHODS: We traced the origin of aggressive PTLs occurring in six patients after allogeneic T cell-depleted stem cell transplantation (allo-SCT). DNA was extracted from donor lymphocytes and PTLs of recipients and amplified with LMP1-specific primers in each case. A comparative sequence analysis of the fingerprint LMP1 region identified in donor lymphocytes and lymphoma was performed. RESULTS: One lymphoma of donor origin occurred after highly selected CD34+ PBSCT and contained the same LMP1 genotype as the donor lymphocytes. Three lymphomas of recipient origin had deletions within the carboxy terminus of LMP1, not identified in the donor strains. All lymphomas occurred in the setting of allo-SCT and had a rapid clinical course. CONCLUSIONS: These results show that highly selected CD34+ PBSCT does not protect against transfer of EBV positive founder cells of donor type PTL and that, after allo-SCT, recipient type PTLs are not uncommon. Outgrowth of recipient type lymphoma may be favoured by LMP1 deletion variant strains present in recipient lymphocytes.

Adult↗

Synergistic activation of simian immunodeficiency virus and human immunodeficiency virus type 1 transcription by retinoic acid and phorbol ester through an NF-kappa B-independent mechanism.

The activation of human immunodeficiency virus type 1 (HIV-1) expression in latently infected cells by exogenous agents is believed to be important in the progression of AIDS. Most factors that are known to activate HIV-1 gene expression increase the binding of NF-kappa B or NF-kappa B-like transcription factors to the HIV-1 core enhancer region. In this report, we demonstrate that retinoic acid (RA) treatment of promonocytic U937 cells stimulates expression from the simian immunodeficiency virus (SIVmac) long terminal repeat (LTR). Furthermore, RA and phorbol 12-myristate 13-acetate (PMA) synergistically stimulated both SIVmac and HIV-1 LTRs to levels of expression comparable to that achieved by the viral transactivator Tat. The cis-acting elements required for a response to RA and PMA cotreatment are located between nucleotides -50 and +1 of SIVmac and between nucleotides -83 and +80 of HIV-1. Thus, the synergistic stimulation induced by RA and PMA is NF-kappa B independent. Analysis of deletion mutants of the SIVmac LTR demonstrates that RA and PMA stimulation cooperates with NF-kappa B and Sp1. An SIVmac LTR-reporter gene construct [pLTR(-50/+466)CAT] lacking NF-kappa B and Sp1 binding sites was not activated by Tat in untreated cells but was activated in cells that were cotreated with RA and PMA. Furthermore, gel retardation assays demonstrated that RA treatment causes a change in the pattern of a cellular factor(s) which binds to the -50 through +1 region of the SIVmac LTR. These data suggest that RA induces a PMA-activatable cellular factor that cooperates with NF-kappa B, Sp1, or Tat to stimulate LTR-directed transcription.

Base Sequence↗

[From acute victimization at chronic victimization: socio-cognitive approach of differential tolerance threshold].

BACKGROUND: Work, for many years reduced to a purely instrumental dimension, proves to be a true microcosm of society, with its informal modes, its emotional networks and its series of evils and dilemmas. This human apprehension of the professional sphere tends to reveal a pole with multiple facets, some of which have long been concealed, but whose individual, social and economic extent can't let people ignore them. This social perception, which contributes to regard work as sacred and makes it impervious to any aggression, should be abandoned. Bearing this in mind, our study endeavours to show that "work" and "victim" are far more overlapping than antagonistic realities; it aims at determining the impact of two aggressive methods via the professional pole, namely: moral harassment at work and armed attacks within bank premises. Such an approach tends to unify health psychology, occupational psychology and victimology, thus opening a breach in the stereotyped view which crystallizes the professional sphere into a kind of representative noose devoid of the most human bases. We then suggest, as a first hypothesis, that the nature of the victimization process, resulting from specific aggressive scenarios, would determine different psychological, physiological and relational consequences, apprehended under the generic expression of tolerance threshold. In other words, "mobbing", through its proactive, intentional and obsessional dimension would tend to lower the victims' threshold more than hold-ups, which are characterized by a reactive aspect, and obey unfavourable socio-economic contingencies. Our research also aims at apprehending this dynamic relationship binding victimization types to tolerance thresholds through two analysing factors. These psychological mediators are derived from Lazarus and Folkman's "transactional model of stress", which postulates that stress would rise from the perception people get of the transaction between the requirements of the situation and their own resources. These modulators would correspond to the social evaluation of the stressor and the adjustment strategies adopted by the victims. We then postulate the fact that these interfering variables would determine a connection between the type of victimization and the series of signs and symptoms generated. In other words, the aversive modes would refer to a process of significance via these interpolated socio-cognitive factors, thus forming a trace of the traumatic event according to the tolerance threshold expressed. More precisely, our assumption consists in postulating that the insidious and latent aspect of harassment which is supposed to support a dispositional attribution of the harasser's intrigues as well as the preferential adoption of coping strategies centred on emotional control, would lower the victims' tolerance threshold further, than a visible and instantaneous hold-up which is supposed to condition an essentially situational perception and the adoption of strategies mainly directed towards the problem. METHOD: Since this study is the subject of a comparative research strategy, its required the constitution of three independent samples: ten harassment victims; seven armed attack victims; ten witnesses, all salaried employees; they had not been subjected to either type of attack but were questioned about a working life event seen as stressful. The three groups, set up according to sex and age considerations, agreed to be subjected to a semi-directive interview. Considering the exploratory nature of this present research, the process proved to be most suitable since, through the filter of the people's subjectivity, it clearly determined the meaning granted by the victim to the aversive situation. In order to comply with a standardization preoccupation, each interview was identically structured using a preset question grid and similar operating conditions. The data collected were then subjected to four levels of analysis. An analysis of contents, centred on a logic-semantic frequency dimension of speech, obtained a simplified representation of the whole of the data. This first level of analysis, supplemented by descriptive statistics, validated, in the second stage, the significance of the differences in the semantic categories. In the third stage, an "analysis of adjacency" associated with a factorial analysis of the correspondences, delineated the differentiating values of the three groups of subjects. A final stage of analysis, centred on a multiaxial dimension [DSM IV ], permitted the constitution of clinical pictures. RESULTS: In accordance with the general assumption, the results show that the victims reveal a dominating presence of mobbing signs related to depression and anxiety symptomatology with an acute emotional threshold. Hold-up victims also show undoubted but significantly less harmful consequences. These victims have turned out to be more centred on the anxious pole and the social and family fields. Moreover, while the victims of harassment unanimously evoke the emergence of a break-up in dynamics conveying a freeze of the social matrix, some of the victims of armed attacks express "secondary benefits" through the setting-up of gregarious dynamics on professional as well as on family level. DISCUSSION: Considering these results, there seems to be a double induction of such a difference. The social evaluation tends to be a first explanatory inference as for the expressed tolerance level. As a matter of fact, the frequential analysis reveals a different perception of the attacker. The supernumerary evocation of dispositional factors, supposing a personal motivation marked with intrigues concealed behind an apparent legitimacy, draws a very personological profile of the harasser. This majority of intrinsic determinants reveals an increase in the causal weight of the harasser; at the same time, it disregards the possible influence of extrinsic factors. In that respect, the harasser is seen as the only instigator of the attacks, which consequently worsens his/her responsibility and culpability. No difference appears between the harasser himself and the hypothetical causes of the aversive situation: the harasser is seen as the source of the attacks and the attacks as the concretization of the harasser's state of mind. On the basis of this report, the victims of harassment tend to amalgamate the personality and the situation. The victims of armed attacks, as for them, are characterized by a more situational evaluation of the stressor, revealing an apparent will to segment the aversive situation: on the one hand the act, and the other the attacker, as though, eventually, the latter was but one element depending on a specific situation. The majority enunciation of extrinsic factors supposes an obvious intention to diffuse the hold-up man's responsibility over contextual attributes. The second inference lies in the strategies used to adjust to the situation. Whatever the type of victimization, the passive coping system reveals as dominating. However, this tendency seems to be more moderate with hold-up victims, who tend to counterbalance the strategies centred on emotional control with strategies directed towards an active resolution of the problem. CONCLUSION: Considering these first results, which call for further study, our impression is that it seems to be relevant to consider the setting-up of psychological therapy programs adapted to the very nature of each victimization case.

Adaptation, Psychological↗

Agonist-induced internalization of leukotriene B(4) receptor 1 requires G-protein-coupled receptor kinase 2 but not arrestins.

The leukotriene B(4) (LTB(4)) receptor (BLT1) becomes desensitized upon repeated agonist stimulation. Little is known, however, about BLT1 internalization, which follows desensitization in most G-protein-coupled receptors (GPCR). In the current study, transiently expressed BLT1 readily internalized, after LTB(4) stimulation, in RBL-2H3 cells that express high levels of endogenous GPCR kinase 2 (GRK2) but did not in COS-7 or human embryonic kidney (HEK) 293 cells, which do not overexpress GRK. The internalization of BLT1 could be blocked in RBL-2H3 cells by coexpressing dominant-negative (DN) GRK2 K220R and could be promoted in HEK293 cells by coexpressing wild-type (WT) GRK2. Coexpression of WT or DN nonvisual arrestins had no effect on BLT1 internalization. Moreover, upon stimulation with LTB(4), BLT1 did not induce arrestin-green fluorescence protein redistribution in either cell type, even in the presence of overexpressed GRK2. Coimmunoprecipitation experiments confirmed that BLT1 could associate with GRK2 but not with arrestins. A C-tail-truncated mutant of BLT1 lost the capacity to internalize and associate with GRK2 upon exposure to LTB(4), suggesting that the C-tail was required for receptor internalization and association with GRK2. Taken together, our results indicate that the C terminus of BLT1 plays a pivotal role in receptor internalization and GRK2 association. Moreover, ligand-induced BLT1 internalization is dependent on GRK2 but independent of arrestins. This may allow differential, cell-type-specific signaling in response to LTB(4), depending on GRK expression levels.

Animals↗