Alveolar macrophages from subjects infected with HIV-1 express macrophage inflammatory protein-1 alpha (MIP-1 alpha): contribution to the CD8+ alveolitis.

A human monoclonal anticardiolipin autoantibody (ACA) of the IgA-k isotype, designated 185/12, is described. The antibody was prepared from peripheral B cells, obtained from a patient with a history of habitual abortion, by immortalization with Epstein-Barr virus (EBV). The antibody displays a strong binding activity to cardiolipin and phosphatidyl L-serine, but not to phosphatidylcholine, phosphatidylinositol, ssDNA and dsDNA. It binds to cardiolipin in a concentration-related and saturable manner (Kd = 3.0 x 10(-8) M). This reaction is dependent upon the presence of bovine serum, and is fully inhibited by cardiolipin vesicles. The 185/12 antibody exhibits different binding patterns to the solid-phase bound cardiolipin-serum complex and to its individual components (cardiolipin and bovine serum). The Bmax of 185/12 binding to the complex (0.968 OD units) is higher than the sum of the Bmax values calculated for each one of the complex components (0.352 + 0.179 = 0.531 OD units). Bovine serum as well as purified beta 2-glycoprotein I (beta 2-GPI) in suspension inhibit the binding of 185/12 to the complex. 185/12 binding capacity increases in direct relation to the rising concentration of beta 2-GPI. Collectively, these data may be interpreted to suggest that 185/12 antibody, which is an IgA isotype, exhibits characteristics usually attributed only to antiphospholipid autoantibodies (APA) of the IgG isotype, that are associated with the clinical spectrum of APA syndrome (APA-S). It is, therefore, possible that autoantibodies of the IgA isotype could play a pathogenic role, which may be different from that of the IgG isotype, in the development of autoimmune phenomena.     

Optimization of an elispot assay to detect cytomegalovirus-specific CD8+ T lymphocytes

Various arguments suggest that CD8+ T lymphocytes play a major role in the control of cytomegalovirus (CMV) infection. The detection of CMV-specific CD8+ T cells may therefore provide additional information about CMV virus detection to predict the risk of development of CMV disease, especially in immunodepressed transplant recipients. We compared and tested various experimental conditions to optimize an enzyme-linked immunospot assay (Elispot) assay for the detection of CMV-specific CD8+ T lymphocytes. The indirect Elispot assay with one six-day in vitro sensitization step was found to be the most sensitive method to detect CMV-specific CD8+ T cells compared to direct Elispot with unfractionated peripheral blood mononuclear cells or purified CD8+ T cells. We showed that low doses of interleukin-2 during the in vitro culture enhanced the sensitivity of this test, and tetramer staining was performed to verify the high efficiency of this in vitro stimulation step. We directly loaded the specific CMV peptide during the Elispot assay and demonstrated that the use of T2 cells did not improve its sensitivity. Elispot for the detection of interferon-gamma appears to be more sensitive and reliable than measurement of tumor necrosis factor alpha or granzyme B. This technique was successfully applied to detect CMV-specific CD8+ T cells in human leukocyte antigen A2 (HLA-A2) and HLA-B7 healthy patients and in one lymphopenic post-transplant patient with positive CMV serology. This highly sensitive test may be a useful tool to assess T-cell immunity directed against CMV in immunodepressed patients.     

Kinematics and eye–head coordination of gaze shifts evoked from different sites in the superior colliculus of the cat

Shifting gaze requires precise coordination of eye and head movements. It is clear that the superior colliculus (SC) is involved with saccadic gaze shifts. Here we investigate its role in controlling both eye and head movements during gaze shifts. Gaze shifts of the same amplitude can be evoked from different SC sites by controlled electrical microstimulation. To describe how the SC coordinates the eye and the head, we compare the characteristics of these amplitude-matched gaze shifts evoked from different SC sites. We show that matched amplitude gaze shifts elicited from progressively more caudal sites are progressively slower and associated with a greater head contribution. Stimulation at more caudal SC sites decreased the peak velocity of the eye but not of the head, suggesting that the lower peak gaze velocity for the caudal sites is due to the increased contribution of the slower-moving head. Eye–head coordination across the SC motor map is also indicated by the relative latencies of the eye and head movements. For some amplitudes of gaze shift, rostral stimulation evoked eye movement before head movement, whereas this reversed with caudal stimulation, which caused the head to move before the eyes. These results show that gaze shifts of similar amplitude evoked from different SC sites are produced with different kinematics and coordination of eye and head movements. In other words, gaze shifts evoked from different SC sites follow different amplitude–velocity curves, with different eye–head contributions. These findings shed light on mechanisms used by the central nervous system to translate a high-level motor representation (a desired gaze displacement on the SC map) into motor commands appropriate for the involved body segments (the eye and the head).     

Low-probability transmission of neocortical and entorhinal impulses through the perirhinal cortex

One model of episodic memory posits that during slow-wave sleep (SWS), the synchronized discharges of hippocampal neurons in relation to sharp waves "replay" activity patterns that occurred during the waking state, facilitating synaptic plasticity in the neocortex. Although evidence of replay was found in the hippocampus in relation to sharp waves, it was never shown that this activity reached the neocortex. Instead, it was assumed that the rhinal cortices faithfully transmit information from the hippocampus to the neocortex and reciprocally. Here, we tested this idea using 3 different approaches. 1) Stimulating electrodes were inserted in the entorhinal cortex and temporal neocortex and evoked unit responses were recorded in between them, in the intervening rhinal cortices. In these conditions, impulse transfer occurred with an extremely low probability, in both directions. 2) To rule out the possibility that this unreliable transmission resulted from the artificial nature of electrical stimuli, crosscorrelation analyses of spontaneous neocortical, perirhinal, and entorhinal firing were performed in unanesthetized animals during the states of waking and SWS. Again, little evidence of propagation could be obtained in either state. 3) To test the idea that propagation occurs only when large groups of neurons are activated within a narrow time window, we computed perievent histograms of neocortical, perirhinal, and entorhinal neuronal discharges around large-amplitude sharp waves. However, these synchronized entorhinal discharges also failed to propagate across the perirhinal cortex. These findings suggest that the rhinal cortices are more than a relay between the neocortex and hippocampus, but rather a gate whose properties remain to be identified.     

Infectious viral diarrheas. Comparison of research methods for rotaviruses

Radioimmunoassay and enzyme immunoassay (EIA) are generally recommended for routine diagnosis of rotavirus infection in childhood gastroenteritis. Expensive and delicate, these techniques are ill-suited for processing a small number of samples. Recently, Latex agglutination tests have been introduced than can be performed by non specialized hospital laboratories. However, some questions have been raised as to the sensitivity and specificity of these tests. We have sought a direct appraisal of latex agglutination testing by comparing two enzyme immunoassays and two latex tests (Rotazyme, Enzygnost-Rotavirus, Rotalex, Slidex Rota-kit). Three comparative studies that involved 1217 stool samples from children with gastroenteritis were carried out. Specificity, sensitivity, of latex tests compared favorably with the more sophisticated EIA, they represent a very convenient alternative for routine laboratory use provided latex tests with low rate of non-specific agglutinations are chosen.     

Killing of Mycobacterium tuberculosis within human monocytes: activation by cytokines and calcitriol.

Human monocytes were isolated and their ability to harbour growth of virulent tubercle bacilli was assessed, in the presence or absence of various immunomodulators. Calcitriol (1,25(OH2), vitamin D3) alone, at doses of 10(-7)-10(-9) M endowed human monocytes with a significant ability to restrict intracellular growth of the tubercle bacilli. Crude immune lymphokines as well as recombinant interferon-gamma (IFN-gamma) endowed monocytes with no tuberculostatic activity. Similarly, other recombinant cytokines tested, notably colony-stimulating factor-1 (CSF-1), interleukin-1 (IL-1), interleukin-3 (IL-3) and interleukin-6 (IL-6) all failed to stimulate anti-tuberculous properties, and even increased growth of the tubercle bacilli in monocytes, in the case of CSF-1. Conversely, incubation of crude lymphokines in combination with calcitriol led to total stasis of the growth of M. tuberculosis. Experiments with recombinant cytokines and immunologically active vitamins showed that a combination of IFN-gamma tumour necrosis factor-alpha and calcitriol induced a significant amount of intramonocyte killing of M. tuberculosis. Addition of this cocktail of factors to already infected monocytes led to substantial killing of tubercle bacilli. These sets of experiments establish clearly that combinations of recombinant cytokines and vitamins may induce substantial intramonocyte killing of M. tuberculosis. The mechanism involved in this killing activity was not clarified.     

Major histocompatibility complex class II-restricted presentation of secreted and endoplasmic reticulum resident antigens requires the invariant chains and is sensitive to lysosomotropic agents

We have tested the involvement of the invariant chains (Ii) p31 and p41 in the presentation of peptides derived from hen egg lysozyme (HEL) constructs targeted to different intracellular compartments within transfected fibroblasts. The endogenous HEL constructs were either present in the cytosol (HELc), secreted (HELs), or linked to the mammalian (KDEL C-terminal sequence that causes retention of HEL in the endoplasmic reticulum (ER)/pre-Golgi recycling compartment (HELr). Using Ii-negative antigen-presenting cells, the presentation of HELr to a HEL 46-61 specific T cell hybridoma was far less efficient than the presentation of the HELs. High levels of Ii expression enhanced drastically the presentation of the HEL 46-61 determinant derived from both HELr and HELs. HELr and HELs presentation was fully sensitive to lysosomotropic agents such as chloroquine, indicating that the formation of complexes between major histocompatibility complex (MHC) class II molecules and determinants derived from endogenous antigens entering the secretory pathway is taking place in an acidic compartment. The degradation and dissociation of Ii might be a prerequisite for the efficient presentation of endogenously derived determinants by MHC class II molecules, as for the presentation of most exogenous antigens. All our results are compatible with the notion that endogenous molecules being translocated into the lumen of the ER could be presented by class II molecules through a processing pathway involving an acidic compartment in which Ii chains dissociate from class II molecules.     

Production of a monoclonal antibody with specificity for deoxynivalenol, 3‐acetyldeoxynivalenol and 15‐acetyldeoxynivalenol

Monoclonal antibodies reactive with deoxynivalenol were generated following the immunization of mice with a deoxynivalenol‐mouse serum albumin conjugate. One of the anti‐deoxynivalenol monoclonal antibodies, designated C6–1, exhibited cross‐reactivity with 3‐acetyldeoxynivalenol and 15‐acetyldeoxynivalenol but not with nivalenol, T‐2 tetraol or scirpentriol. An indirect competitive ELISA based on this monoclonal antibody gave 50% inhibition values of 0–6 μg ml^‐1 for deoxynivalenol, 0–2 μg ml^‐1 for 15‐acetyldeoxynivalenol and 10 μg ml^‐1 for 3‐acetyldeoxynivalenol.     

Mg2+ Transporters in Digestive Cancers

Despite magnesium (Mg²⁺) representing the second most abundant cation in the cell, its role in cellular physiology and pathology is far from being elucidated. Mg²⁺ homeostasis is regulated by Mg²⁺ transporters including Mitochondrial RNA Splicing Protein 2 (MRS2), Transient Receptor Potential Cation Channel Subfamily M, Member 6/7 (TRPM6/7), Magnesium Transporter 1 (MAGT1), Solute Carrier Family 41 Member 1 (SCL41A1), and Cyclin and CBS Domain Divalent Metal Cation Transport Mediator (CNNM) proteins. Recent data show that Mg²⁺ transporters may regulate several cancer cell hallmarks. In this review, we describe the expression of Mg²⁺ transporters in digestive cancers, the most common and deadliest malignancies worldwide. Moreover, Mg²⁺ transporters’ expression, correlation and impact on patient overall and disease-free survival is analyzed using Genotype Tissue Expression (GTEx) and The Cancer Genome Atlas (TCGA) datasets. Finally, we discuss the role of these Mg²⁺ transporters in the regulation of cancer cell fates and oncogenic signaling pathways.     

Posttraumatic Stress Disorder Following Myocardial Infarction: A Systematic Review

The objective of the present review is to provide an overview of existing research that has reported on the association between posttraumatic stress disorder (PTSD) and ischemic heart disease. Specific focus is given to the incidence of PTSD following myocardial infarction (MI). A systematic review using Preferred Reporting Items for Systematic reviews and Meta‐Analysis (PRISMA) guidelines was performed by searching four bibliographic databases: PubMed, PsychINFO, ScienceDirect, and ProQuest Dissertations and Theses. A total of 39 articles were included in this literature review. The results of these studies suggest that the occurrence of an acute cardiac event is likely to contribute to the development of PTSD. Not only is this type of psychiatric disorder associated with significant suffering and impaired quality of life, but it is also a predictor of an increased risk of recurrent adverse cardiovascular events and mortality. Screening, assessment, and treatment of PTSD and posttraumatic stress symptoms following a major cardiac event are critical for offsetting potential deleterious psychological and physical consequences.