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1.
Orbit ; : 1-5, 2023 Oct 14.
Article in English | MEDLINE | ID: mdl-37837294

ABSTRACT

Paraneoplastic syndromes (PNSs) are remote effects of the primary tumor on tissues and organs, not related to direct invasion or metastasis. Ophthalmological involvement has been reported in 0.01-0.1% cases of PNSs. It may present as retinopathy, optic neuritis, myasthenia-like syndromes, or orbital myositis (OM), among others. An 89-year-old male with bilateral ocular pain and chemosis, was given an initial diagnosis of bilateral acute conjunctivitis. After 5 days, the patient presented worsening of the pain and bilateral complete ophthalmoplegia. Cranial CT scan showed diffuse bilateral thickening of the four rectus muscles. Inflammatory markers, thyroid hormones, and thyroid antibodies were normal. An abdominal ultrasound test was performed, observing a mass in the right kidney. After confirmation of the lesion with a CT scan, the radiological characteristics of the lesion were highly suggestive of renal cell carcinoma. Treatment with intravenous corticosteroids was ensued with complete resolution of all ophthalmological symptoms. Paraneoplastic orbital panmyositis was first described in 1994. Since then it has been reported scarcely, remaining an extremely rare entity. To our knowledge, this is the first report of its association with renal cell carcinoma. In the absence of inflammatory or dysthyroid blood markers, bilateral orbital panmyositis warrants further investigation for a possible underlying oncological pathology.

2.
Neurosci Biobehav Rev ; 102: 299-307, 2019 07.
Article in English | MEDLINE | ID: mdl-31047892

ABSTRACT

Altered cognitive performance is considered an intermediate phenotype mediating early life adversity (ELA) effects on later-life development of mental disorders, e.g. depression. Whereas most human studies are limited to correlational conclusions, rodent studies can prospectively investigate how ELA alters cognitive performance in several domains. Despite the volume of reports, there is no consensus on i) the behavioral domains being affected by ELA and ii) the extent of these effects. To test how ELA (here: aberrant maternal care) affects specific behavioral domains, we used a 3-level mixed-effect meta-analysis, and thoroughly explored heterogeneity with MetaForest, a novel machine-learning approach. Our results are based on >400 independent experiments, involving ∼8600 animals. Especially in males, ELA promotes memory formation during stressful learning but impairs non-stressful learning. Furthermore, ELA increases anxiety-like and decreases social behavior. The ELA phenotype was strongest when i) combined with other negative experiences ("hits"); ii) in rats; iii) in ELA models of ∼10days duration. All data is easily accessible with MaBapp (https://osf.io/ra947/), allowing researchers to run tailor-made meta-analyses, thereby revealing the optimal choice of experimental protocols and study power.


Subject(s)
Anxiety , Behavior, Animal , Disease Models, Animal , Memory , Social Behavior , Stress, Psychological , Animals , Female , Male , Anxiety/physiopathology , Memory/physiology , Phenotype , Rodentia/physiology , Stress, Psychological/physiopathology
3.
J Phys Chem A ; 117(2): 361-9, 2013 Jan 17.
Article in English | MEDLINE | ID: mdl-23249289

ABSTRACT

Steady-state and picosecond time-resolved X-ray absorption spectroscopy is used to study the ground and lowest triplet states of [ReX(CO)(3)(bpy)](n+), X = Etpy (n = 1), Cl, or Br (n = 0). We demonstrate that the transient spectra at both the Re L(3)- and Br K-edges show the emergence of a pre-edge feature, absent in the ground-state spectrum, which is associated with the electron hole created in the highest occupied molecular orbital following photoexcitation. Importantly, these features have the same dynamics, confirming previous predictions that the low-lying excited states of these complexes involve a two-center charge transfer from both the Re and the ligand, X. We also demonstrate that the DFT optimized ground and excited structures allow us to reproduce the experimental XANES and EXAFS spectra. The ground-state structural refinement shows that the Br atom contributes very little to the latter, whereas the Re-C-O scattering paths are dominant due to the so-called focusing effect. For the excited-state spectrum, the Re-X bond undergoes one of the largest changes but still remains a weak contribution to the photoinduced changes of the EXAFS spectrum.

4.
Phys Rev Lett ; 109(7): 074301, 2012 Aug 17.
Article in English | MEDLINE | ID: mdl-23006372

ABSTRACT

In the Leidenfrost effect, liquid drops deposited on a hot surface levitate on a thin vapor cushion fed by evaporation of the liquid. This vapor layer forms a concave depression in the drop interface. Using laser-light interference coupled to high-speed imaging, we measured the radius, curvature, and height of the vapor pocket, as well as nonaxisymmetric fluctuations of the interface for water drops at different temperatures. The geometry of the vapor pocket depends primarily on the drop size and not on the substrate temperature.

5.
Eye (Lond) ; 25(1): 105-12, 2011 Jan.
Article in English | MEDLINE | ID: mdl-21057522

ABSTRACT

PURPOSE: Accurate assessment of the amount of macular pigment (MPOD) is necessary to investigate the role of carotenoids and their assumed protective functions. High repeatability and reliability are important to monitor patients in studies investigating the influence of diet and supplements on MPOD. We evaluated the Macuscope (Macuvision Europe Ltd., Lapworth, Solihull, UK), a recently introduced device for measuring MPOD using the technique of heterochromatic flicker photometry (HFP). We determined agreement with another HFP device (QuantifEye; MPS 9000 series: Tinsley Precision Instruments Ltd., Croydon, Essex, UK) and a fundus reflectance method. METHODS: The right eyes of 23 healthy subjects (mean age 33.9 ± 15.1 years) were measured. We determined agreement with QuantifEye and correlation with a fundus reflectance method. Repeatability of QuantifEye was assessed in 20 other healthy subjects (mean age 32.1 ± 7.3 years). Repeatability was also compared with measurements by a fundus reflectance method in 10 subjects. RESULTS: We found low agreement between test and retest measurements with Macuscope. The average difference and the limits of agreement were -0.041 ± 0.32. We found high agreement between test and retest measurements of QuantifEye (-0.02 ± 0.18) and the fundus reflectance method (-0.04 ± 0.18). MPOD data obtained by Macuscope and QuantifEye showed poor agreement: -0.017 ± 0.44. For Macuscope and the fundus reflectance method, the correlation coefficient was r = 0.05 (P = 0.83). A significant correlation of r = 0.87 (P<0.001) was found between QuantifEye and the fundus reflectance method. CONCLUSIONS: Because repeatability of Macuscope measurements was low (ie, wide limits of agreement) and MPOD values correlated poorly with the fundus reflectance method, and agreed poorly with QuantifEye, the tested Macuscope protocol seems less suitable for studying MPOD.


Subject(s)
Macula Lutea/chemistry , Photometry/methods , Retinal Pigments/analysis , Adult , Female , Fundus Oculi , Humans , Male , Middle Aged , Photometry/instrumentation , Reproducibility of Results
6.
J Chem Phys ; 130(12): 124520, 2009 Mar 28.
Article in English | MEDLINE | ID: mdl-19334864

ABSTRACT

We present a novel analysis of time-resolved extended x-ray absorption fine structure (EXAFS) spectra based on the fitting of the experimental transients obtained from optical pump/x-ray probe experiments. We apply it to the analysis of picosecond EXAFS data on aqueous [Fe(II)(bpy)(3)](2+), which undergoes a light induced conversion from its low-spin (LS) ground state to the short-lived (tau approximately 650 ps) excited high-spin (HS) state. A series of EXAFS spectra were simulated for a collection of possible HS structures from which the ground state fit spectrum was subtracted to generate transient difference absorption (TA) spectra. These are then compared with the experimental TA spectrum using a least-squares statistical analysis to derive the structural change. This approach reduces the number of required parameters by cancellation in the differences. It also delivers a unique solution for both the fractional population and the extracted excited state structure. We thus obtain a value of the Fe-N bond elongation in the HS state with subpicometer precision (0.203+/-0.008 A).


Subject(s)
Ferrous Compounds/chemistry , Absorption , Spectrum Analysis , Time Factors , Water/chemistry , X-Rays
7.
Science ; 323(5913): 489-92, 2009 Jan 23.
Article in English | MEDLINE | ID: mdl-19074309

ABSTRACT

X-ray absorption spectroscopy is a powerful probe of molecular structure, but it has previously been too slow to track the earliest dynamics after photoexcitation. We investigated the ultrafast formation of the lowest quintet state of aqueous iron(II) tris(bipyridine) upon excitation of the singlet metal-to-ligand-charge-transfer (1MLCT) state by femtosecond optical pump/x-ray probe techniques based on x-ray absorption near-edge structure (XANES). By recording the intensity of a characteristic XANES feature as a function of laser pump/x-ray probe time delay, we find that the quintet state is populated in about 150 femtoseconds. The quintet state is further evidenced by its full XANES spectrum recorded at a 300-femtosecond time delay. These results resolve a long-standing issue about the population mechanism of quintet states in iron(II)-based complexes, which we identify as a simple 1MLCT-->3MLCT-->5T cascade from the initially excited state. The time scale of the 3MLCT-->5T relaxation corresponds to the period of the iron-nitrogen stretch vibration.

8.
Genes Brain Behav ; 7(2): 184-92, 2008 Mar.
Article in English | MEDLINE | ID: mdl-17608702

ABSTRACT

The importance of maternal care in shaping an individual's phenotype in health and disease is becoming more and more apparent in both human and animal studies. However, in mouse studies using inbred strains or knockout mice to analyze the genetic influences on the development of normal and aberrant behavioral phenotypes, maternal behavior is very poorly characterized and often ignored. This study provides an extensive analysis of spontaneous maternal behavior of inbred mice in three conditions: (1) comparing two commonly used strains, (2) analyzing the impact of adopting pups from the same strain (intrastrain cross-fostering) and (3) analyzing the impact of adopting pups from a different strain (interstrain cross-fostering). For each condition, maternal behavior was analyzed continuously over 23-h periods on postnatal days 2, 4, 6 and 9. We report that (1) the maternal behavior of C57BL/6J and DBA/2J dams toward their biological offspring is highly similar, (2) intrastrain cross-fostering has minimal impact on maternal behavior of C57BL/6J and DBA/2J dams, (3) interstrain cross-fostering does not modify the strain differences in maternal care observed between AKR and C3H/He mothers and (4) the pup strain does influence the amount of maternal behavior shown by both mothers in interstrain cross-fostering. These latter findings demonstrate that both mother strain and pup strain are key determinants of maternal behavior.


Subject(s)
Crosses, Genetic , Maternal Behavior/physiology , Animals , Animals, Newborn , Female , Foster Home Care , Housing, Animal , Mice , Mice, Inbred AKR/genetics , Mice, Inbred C57BL/genetics , Mice, Inbred DBA/genetics , Species Specificity , Weaning
9.
Phys Rev Lett ; 97(17): 173003, 2006 Oct 27.
Article in English | MEDLINE | ID: mdl-17155471

ABSTRACT

The rovibronic structure in the photoelectron spectrum of CH4 has been assigned in infrared-vacuum ultraviolet double-resonance experiments and analyzed using an effective tunneling-rotation Hamiltonian. Comparison of theoretical and experimental level structures of CH4+ reveals the effect of the geometric phase and establishes that at low energies, the structure and dynamics are governed by a large-amplitude tunneling motion connecting equivalent minima of C(2v) geometry. The rotationless ground state of CH4+ is a tunneling doublet of triply degenerate levels and the lowest level has rovibronic symmetry F2. The adiabatic ionization energy of CH4 is 101753.0(15) cm(-1).

10.
Cell Immunol ; 235(1): 39-45, 2005 May.
Article in English | MEDLINE | ID: mdl-16083869

ABSTRACT

CD4+ T cell proliferation depends on the balance between NO and extra-cellular superoxide (O2-). By reducing NO bio-availability, O2- promotes splenic T cell proliferation and immune response intensity. Here, we show that spleen cells from naïve mice produced neither NO nor O2- during T cell activation, but Gr-1+ splenocytes from primed mice regulated Ag-specific T cell expansion via production of both molecules. Purified splenic Gr-1+ cells included mostly granulocytes at various stages of maturation, as well as monocytes. Activation or recruitment of regulatory Gr-1+ cells was dependent on immunization with CFA. Importantly, these regulatory cells were not detected in draining lymph nodes. These data suggest that innate Gr-1+ splenic cells regulate adaptive immunity.


Subject(s)
Cell Proliferation , Receptors, Chemokine/biosynthesis , Spleen/cytology , T-Lymphocytes/cytology , T-Lymphocytes/immunology , Animals , Freund's Adjuvant , Immunologic Factors/biosynthesis , Immunologic Factors/physiology , Lipids , Lymphocyte Activation/immunology , Major Histocompatibility Complex/physiology , Mice , Mice, Inbred C57BL , Mice, Transgenic , Mycobacterium tuberculosis/immunology , Nitric Oxide/biosynthesis , Nitric Oxide/physiology , Resting Phase, Cell Cycle/immunology , Spleen/immunology , Spleen/metabolism , Superoxides/metabolism , Superoxides/pharmacology , T-Lymphocytes/metabolism
11.
Neuroscience ; 110(3): 489-504, 2002.
Article in English | MEDLINE | ID: mdl-11906788

ABSTRACT

Estradiol exerts beneficial effects on neurodegenerative disorders associated with the decline of cognitive performance. The present study was designed to further investigate the effect of 17beta-estradiol on learning and memory, and to evaluate its neuroprotective action on cholinergic cells of the nucleus basalis magnocellularis, a neural substrate of cognitive performance. Female rats were ovariectomized at an age of 6 months. Three weeks later they received injections of either a mid-physiological dose of 17beta-estradiol or vehicle (oil), every other day for 2 weeks. The effect of estradiol on cognitive performance was tested in two associative learning paradigms. In the two-way active shock avoidance task estradiol-replaced animals learned significantly faster, while in the passive shock avoidance test no differences were observed between the experimental groups. Subsequent unilateral infusion of N-methyl-D-aspartate in the nucleus basalis magnocellularis resulted in a significant loss of cholinergic neurons concomitant with the loss of their fibers invading the somatosensory cortex. Estradiol treatment did not affect the total number of choline-acetyltransferase-immunoreactive neurons and their coexpression of the p75 low-affinity neurotrophin receptor either contralateral or ipsilateral to the lesion. In contrast, cholinergic fiber densities in estradiol-treated animals were greater both in the contralateral and ipsilateral somatosensory cortices as was detected by quantitative choline-acetyltransferase and vesicular acetylcholine transporter immunocytochemistry. However, estradiol treatment did not affect the lesion-induced relative percentage loss of cholinergic fibers. A significant decline of synaptophysin immunoreactivity paralleled the cholinergic damage in the somatosensory cortex of oil-treated animals, whereas an almost complete preservation of synaptic density was determined in estradiol-treated rats. Our results indicate that estradiol treatment enhances the cortical cholinergic innervation but has no rescuing effect on cholinergic nerve cells in the basal forebrain against excitotoxic damage. Nevertheless, estradiol may restore or maintain synaptic density in the cerebral cortex following cholinergic fiber loss. This estradiol effect may outweigh the lack of cellular protection on cholinergic cells at the functional level.


Subject(s)
Basal Nucleus of Meynert/drug effects , Cerebral Cortex/drug effects , Cholinergic Fibers/drug effects , Estradiol/pharmacology , Membrane Transport Proteins , Memory/drug effects , Neuroprotective Agents/pharmacology , Presynaptic Terminals/drug effects , Vesicular Transport Proteins , Acetylcholinesterase/metabolism , Animals , Avoidance Learning/drug effects , Avoidance Learning/physiology , Basal Nucleus of Meynert/metabolism , Basal Nucleus of Meynert/pathology , Carrier Proteins/metabolism , Cerebral Cortex/metabolism , Cerebral Cortex/pathology , Choline O-Acetyltransferase/metabolism , Cholinergic Fibers/metabolism , Cholinergic Fibers/pathology , Cognition Disorders/drug therapy , Cognition Disorders/metabolism , Cognition Disorders/physiopathology , Estradiol/metabolism , Female , Immunohistochemistry , Memory/physiology , Neurodegenerative Diseases/drug therapy , Neurodegenerative Diseases/metabolism , Neurodegenerative Diseases/physiopathology , Neurotoxins/pharmacology , Ovariectomy , Presynaptic Terminals/metabolism , Presynaptic Terminals/pathology , Rats , Rats, Wistar , Receptor, Nerve Growth Factor/metabolism , Synaptophysin/metabolism , Vesicular Acetylcholine Transport Proteins
12.
Int Immunopharmacol ; 1(8): 1491-500, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11515814

ABSTRACT

In this article, the controversial role of nitric oxide (NO) in T helper (Th) cell activation and T-cell-dependent immunity will be discussed with an emphasis on immunosuppression by NO. NO is generated by antigen-presenting cells (APC) during the process of antigen presentation to T cells. In mouse models, activation of the inducible NO synthase (iNOS) in APC is triggered by Th1-cell-derived IFN-gamma, in combination with other soluble or membrane-associated T-cell factors. The NO so-produced inhibits T-cell proliferation, while it does not inhibit T cell cytokine production. NO blocks T-cell proliferation during G1/S transition. In mouse models of T-cell-mediated autoimmunity such as myelin antigen-induced EAE, the disease is exacerbated by genetic deletion of iNOS, indicating that NO suppresses T-cell-mediated immunity in vivo. Recent studies reveal that interaction with superoxide diminishes the T-cell regulatory activity of NO. The role for NADPH oxidase as a source for NO-inhibiting superoxide is discussed. In conclusion, NO plays an important regulatory role in the induction phase of T-cell-mediated immunity. Superoxide may enhance T-cell-mediated immunity by preventing the immunosuppressive activity of NO.


Subject(s)
Immunity, Cellular , Nitric Oxide/physiology , T-Lymphocytes, Helper-Inducer/immunology , T-Lymphocytes, Helper-Inducer/metabolism , Animals , Humans
13.
J Immunol ; 164(10): 5177-83, 2000 May 15.
Article in English | MEDLINE | ID: mdl-10799876

ABSTRACT

NO, which suppresses T cell proliferation, may be inactivated by superoxide (O2-) due to their strong mutual affinity. To examine this possibility, preactivated Th clones were cocultured with stimulated macrophages. PMA neutralized the inhibitory activity of NO, which was dependent on extracellular O2- production. In contrast, macrophages from p47phox -/- (pKO) mice, which lack functional NADPH oxidase, retained their NO-dependent inhibition of T cell proliferation upon stimulation with PMA, indicating that NADPH oxidase is the major source of NO-inactivating O2- in this system. To examine the NO-O2- interaction in vivo, the role of NADPH oxidase in experimental autoimmune encephalomyelitis was studied in pKO mice. No clinical or histological signs were observed in the pKO mice. Neither a bias in Th subsets nor a reduced intensity of T cell responses could account for the disease resistance. Although spleen cells from pKO mice proliferated poorly in response to the immunogen, inhibition of NO synthase uncovered a normal proliferative response. These results indicate that NO activity may play a critical role in T cell responses in pKO mice and that in normal spleens inhibition of T cell proliferation by NO may be prevented by simultaneous NADPH oxidase activity.


Subject(s)
Encephalomyelitis, Autoimmune, Experimental/immunology , Immunosuppressive Agents/antagonists & inhibitors , Immunosuppressive Agents/pharmacology , NADPH Oxidases/genetics , Nitric Oxide/antagonists & inhibitors , Nitric Oxide/physiology , Superoxides/pharmacology , T-Lymphocytes, Helper-Inducer/immunology , Adjuvants, Immunologic/genetics , Adjuvants, Immunologic/physiology , Animals , Cells, Cultured , Coculture Techniques , Encephalomyelitis, Autoimmune, Experimental/enzymology , Encephalomyelitis, Autoimmune, Experimental/genetics , Encephalomyelitis, Autoimmune, Experimental/prevention & control , Lymph Nodes/cytology , Lymph Nodes/immunology , Lymphocyte Activation/genetics , Lymphocyte Activation/immunology , Macrophages, Peritoneal/enzymology , Macrophages, Peritoneal/immunology , Macrophages, Peritoneal/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Myelin Proteins , Myelin-Associated Glycoprotein/immunology , Myelin-Oligodendrocyte Glycoprotein , NADPH Oxidases/physiology , Nitric Oxide/metabolism , Superoxides/metabolism , Tetradecanoylphorbol Acetate/antagonists & inhibitors , Tetradecanoylphorbol Acetate/pharmacology
14.
Cell Immunol ; 199(1): 43-9, 2000 Jan 10.
Article in English | MEDLINE | ID: mdl-10675274

ABSTRACT

To examine how macrophage-derived nitric oxide (NO) affects T helper (Th) cell activity, T cell clones representing Th1 and Th2 subsets were activated before exposure to stimulated peritoneal macrophages or microglia. Both Th subsets were similarly sensitive to inhibition by NO, indicating that macrophage-derived NO regulates the proliferation of activated Th1 and Th2 cells equally well. Since IFN-gamma production remained intact in NO-treated Th1 cells, we studied whether NO was produced during antigen-specific activation of Th1 cells by unstimulated macrophages. Indeed, T cell proliferation only occurred when a NO synthase inhibitor was included, while IFN-gamma was essential for the induction of NO. These studies demonstrate that macrophages produce NO following antigen presentation to Th1 cells and that macrophage-derived NO inhibits Th1 and Th2 cell proliferation without inhibiting cytokine production.


Subject(s)
Antigens/immunology , Lymphocyte Activation/immunology , Macrophages, Peritoneal/metabolism , Nitric Oxide/metabolism , Th1 Cells/immunology , Th2 Cells/immunology , Animals , Apoptosis/drug effects , Cell Division/drug effects , Cells, Cultured , Coculture Techniques , Female , Interferon-gamma/biosynthesis , Interleukin-5/biosynthesis , Lymphocyte Activation/drug effects , Macrophage Activation , Macrophages, Peritoneal/drug effects , Macrophages, Peritoneal/enzymology , Macrophages, Peritoneal/immunology , Mice , Mice, Inbred Strains , Microglia/drug effects , Microglia/enzymology , Microglia/immunology , Microglia/metabolism , Nitric Oxide Synthase/antagonists & inhibitors , Nitric Oxide Synthase/metabolism , Peptides/immunology , Th1 Cells/cytology , Th1 Cells/drug effects , Th1 Cells/metabolism , Th2 Cells/cytology , Th2 Cells/drug effects , Th2 Cells/metabolism , omega-N-Methylarginine/pharmacology
15.
Cell Immunol ; 206(2): 125-35, 2000 Dec 15.
Article in English | MEDLINE | ID: mdl-11161444

ABSTRACT

The induction and role of nitric oxide (NO) during antigen presentation by macrophages to T helper (Th) cell subsets was examined. When cultured with Th1 clones, macrophage APC produced NO only in the presence of cognate Ag, which in turn suppressed T cell proliferation. IFN-gamma production by the activated Th1 cells was essential for the induction of NO. Th2 cells presented with the same cognate Ag did not induce NO production and proliferated uninhibited. Coactivation of Th1 and Th2 cells specific for the same Ag indicated that Th2 cells did not inhibit NO production, but were sensitive to NO induced by stimulated Th1 cells. Antigenic activation of Th2 cells in the presence of rIFN-gamma resulted in NO-mediated inhibition of proliferation. Th2 cells provided only a cell-associated cofactor, whereas Th1 cells secreted a soluble cofactor for IFN-gamma as well, i.e., TNF-alpha. Finally, a role for IFN-gamma and NO during immune responses was studied in spleen cells obtained from immunized IFN-gamma(-/-) mice. NO production and subsequent inhibition of Ag-specific proliferation ex vivo was observed only after the addition of rIFN-gamma. These studies suggest an IFN-gamma-dependent regulatory role for NO during Ag-specific Th cell activation involving macrophages, with obvious implications for Th subset-dependent immune responses in general.


Subject(s)
Antigen Presentation , Growth Inhibitors/biosynthesis , Interferon-gamma/physiology , Lymphocyte Activation/immunology , Macrophages, Peritoneal/immunology , Nitric Oxide/biosynthesis , Th1 Cells/immunology , Th2 Cells/immunology , Animals , Cell-Free System/immunology , Cells, Cultured , Clone Cells , Coculture Techniques , Female , Growth Inhibitors/physiology , Immunosuppressive Agents/metabolism , Immunosuppressive Agents/pharmacology , Interferon-gamma/pharmacology , Macrophages, Peritoneal/metabolism , Mice , Mice, Inbred C57BL , Mice, Inbred Strains , Nitric Oxide/physiology , Recombinant Proteins/pharmacology , Spleen/cytology , Spleen/immunology , Th1 Cells/cytology , Th1 Cells/metabolism , Th2 Cells/cytology , Th2 Cells/metabolism
16.
J Neuroimmunol ; 95(1-2): 1-7, 1999 Mar 01.
Article in English | MEDLINE | ID: mdl-10229110

ABSTRACT

Peroxynitrite is formed by the reaction of nitric oxide (NO) and superoxide. Since widespread peroxynitrite activity was observed during experimental allergic encephalomyelitis (EAE), the effect of this strong lipid-peroxidizing agent on myelin integrity was examined. Incubation of myelin suspensions with the peroxynitrite donor 3-morpholinosydnonimine (SIN-1) resulted in the formation of the lipid peroxidation product, malondialdehyde (MDA). MDA formation was inhibited in the presence of butylated hydroxytoluene, which interrupts the progression of the lipid peroxidation chain reaction. Superoxide dismutase inhibited the effect of SIN-1, which indicates a role for superoxide, and contradicts a role for its dismutation product, hydrogen peroxide. The latter was confirmed by the failure of the catalase to inhibit MDA formation. Neither NO nor superoxide alone induced significant MDA formation in myelin, indicating that peroxynitrite formation is required for myelin-lipid peroxidation. Interestingly, NO actually inhibited lipid peroxidation in myelin, as demonstrated using simple NO donors. On the other hand, the simultaneous production of superoxide, as achieved with the NO-donor SIN-1, negated the inhibitory effect of NO. Finally, the production of isoprostanes, novel products generated during lipid peroxidation, was examined. Peroxynitrite-induced peroxidation of myelin resulted in isoprostane formation. Furthermore, increased levels of F2-isoprostanes and neuroprostanes were observed in spinal cords of mice during early progressive stages of autoimmune encephalomyelitis.


Subject(s)
Central Nervous System/metabolism , Myelin Sheath/metabolism , Nitrates/metabolism , Nitric Oxide/metabolism , Oxidants/metabolism , Animals , Central Nervous System/immunology , Dinoprost/analogs & derivatives , Dinoprost/metabolism , Encephalomyelitis, Autoimmune, Experimental/immunology , Encephalomyelitis, Autoimmune, Experimental/metabolism , F2-Isoprostanes , Lipid Peroxidation/drug effects , Lipid Peroxidation/immunology , Mice , Molsidomine/analogs & derivatives , Molsidomine/pharmacology , Myelin Proteins/metabolism , Myelin Sheath/immunology , Nitric Oxide Donors/pharmacology , Penicillamine/analogs & derivatives , Penicillamine/pharmacology
17.
Cell Immunol ; 193(2): 194-201, 1999 May 01.
Article in English | MEDLINE | ID: mdl-10222062

ABSTRACT

To study the effect of nitric oxide (NO) on the activity of Th subsets, cloned Th1 and Th2 lymphocytes were stimulated in the presence of an NO donor. NO, when present from the start of incubation, inhibited the proliferation of both Th subsets dose-dependently, achieving complete inhibition at a relatively low level. The addition of NO 24 h after the onset of T cell stimulation also resulted in reduced proliferation of both Th subsets, suggesting that NO affects a late process during T cell activation. Stimulation of T cells in the presence of NO did not induce apoptosis at the concentrations that completely inhibited proliferation, although apoptosis became evident at higher NO concentrations. The secretion of several cytokines (i.e., IFN-gamma, IL-4, and IL-5) was slightly upregulated, while IL-2 production was modestly inhibited in the presence of NO. However, exogenous IL-2 did not reverse the NO-induced inhibition of T cell proliferation, nor did additional stimulation with phorbol esters. Finally, expression of IL-2R was modestly decreased in the presence of NO, although TCR expression was not affected. These studies demonstrate that relatively low concentrations of NO induce a strong and specific inhibition of T cell proliferation in both Th subsets, suggesting that local NO production may regulate Th-mediated tissue inflammation.


Subject(s)
Cytokines/metabolism , Nitric Oxide/pharmacology , T-Lymphocyte Subsets/drug effects , Th1 Cells/drug effects , Th2 Cells/drug effects , Antigens, Differentiation, T-Lymphocyte/biosynthesis , Apoptosis/drug effects , Cell Division/drug effects , Clone Cells , Dose-Response Relationship, Drug , Interferon-gamma/metabolism , Interleukins/metabolism , Myelin Proteins/immunology , T-Lymphocyte Subsets/cytology , Th1 Cells/cytology , Th1 Cells/immunology , Th2 Cells/cytology , Th2 Cells/immunology
18.
Virology ; 245(2): 270-80, 1998 Jun 05.
Article in English | MEDLINE | ID: mdl-9636366

ABSTRACT

Interleukin 10 (IL-10) is an important anti-inflammatory cytokine. To examine its role in virus-induced encephalomyelitis, IL-10-deficient (IL-10 -/-) mice were infected with a neurotropic strain of mouse hepatitis virus (JHMV). JHMV-infected IL-10 -/- mice, compared to IL-4 -/- and syngeneic C57BL/6 mice, exhibited increased morbidity and mortality. Virus was cleared from the CNS of all groups of mice with equal kinetics by day 9 postinfection and the lack of either IL-4 or IL-10 did not alter the distribution of viral antigen, suggesting a lack of correlation between viral replication and the increased clinical disease in IL-10 -/- mice. In moribund IL-10 -/- mice, a moderate increase in mononuclear cell infiltration was correlated with increased expression of tumor necrosis factor-alpha, interferon-gamma, and inducible nitric oxide synthase mRNAs. In the small percentage of IL-10 -/- mice that survived, no differences in either demyelination or inflammation were observed. Together, these results suggest that IL-10 is not required for viral clearance, and although it appears to be one of the mechanisms responsible for inhibiting the extent of inflammation in the CNS during acute JHMV infection, it has little role in the eventual resolution of CNS inflammatory responses.


Subject(s)
Coronavirus Infections/physiopathology , Encephalomyelitis/physiopathology , Encephalomyelitis/virology , Interleukin-10/physiology , Murine hepatitis virus , Animals , Coronavirus Infections/mortality , Encephalomyelitis/mortality , Interferon-gamma/physiology , Mice , Mice, Inbred C57BL , Mice, Knockout , Nitric Oxide Synthase/physiology , Nitric Oxide Synthase Type II , Tumor Necrosis Factor-alpha/physiology
19.
J Neuroimmunol ; 77(1): 1-7, 1997 Jul.
Article in English | MEDLINE | ID: mdl-9209262

ABSTRACT

Nitric oxide (NO) production has been associated with disease activity in multiple sclerosis and experimental autoimmune encephalomyelitis (EAE). This free radical can be transformed by superoxide to peroxynitrite, an extremely toxic oxidant which causes lipid peroxidation. In addition, peroxynitrite nitrates tyrosine residues, resulting in nitrotyrosine, which can be identified immunohistochemically. The results of this study indicate that peroxynitrite is formed very early during EAE development, correlating with clinical disease activity. Nitrotyrosine-positive cells display a widespread distribution in brain and spinal cord during severe disease and are associated with both perivascular infiltrates and parenchymal sites. Double-staining procedures demonstrated that a subpopulation of CD11b-positive cells (macrophages/microglia) reacted with nitrotyrosine antibodies. Immunostaining for inducible NO synthase demonstrated a similar distribution as nitrotyrosine staining. These experiments indicate that peroxynitrite is formed during progressive stages of disease activity.


Subject(s)
Neuritis, Autoimmune, Experimental/immunology , Nitrates/immunology , Nitrates/metabolism , Animals , Antibody Specificity , Brain/cytology , Disease Progression , Encephalomyelitis, Autoimmune, Experimental/immunology , Encephalomyelitis, Autoimmune, Experimental/metabolism , Free Radicals/immunology , Free Radicals/metabolism , Immunohistochemistry , Lipid Peroxidation/immunology , Mice , Mice, Inbred Strains , Neuritis, Autoimmune, Experimental/metabolism , Neurons/immunology , Neurons/metabolism , Nitric Oxide/immunology , Nitric Oxide/metabolism , Spinal Cord/cytology , Staining and Labeling , Tyrosine/analogs & derivatives , Tyrosine/immunology , Tyrosine/metabolism
20.
Virology ; 225(2): 339-46, 1996 Nov 15.
Article in English | MEDLINE | ID: mdl-8918920

ABSTRACT

The CD4+ T-cell-restricted recognition of the structural proteins in the JHM strain of MHV (JHMV) was compared between two mouse strains. Following immunization with inactivated JHMV, all proteins elicited an immune response in both C57BL/6 and BALB/c mouse strains, except the nucleocapsid (N) protein, which was not immunogenic in C57BL/6 mice. T-cell lines and clones were derived from BALB/c mice immunized with UV-inactivated JHMV, to determine the epitope(s) for CD4+ T cells. The N protein appears immunodominant, since all T-cell lines and clones derived therefrom recognized this protein. To locate epitope-containing domains within the N protein, truncated N-protein fragments expressed in vaccinia constructs were used to stimulate the T-cell clones. Five independent T-cell clones recognized three separate N-protein domains: 1-133, 134-249, and 250-306. Since three of five clones recognized the last domain, its sequence was studied in more detail by constructing overlapping synthetic peptides covering this region. A single epitope was localized within the peptide comprising the N-protein residues 266-279. Its restriction element was identified as I-E(d) using mAb to I-E(d) and I-A(d). In addition, peptide N266-279 contains the motif for binding to I-E(d). This peptide elicited proliferative responses following immunization with JHMV, confirming its recognition in the complete virus. In addition, peptide N266-279 was recognized by T-cell clones that express differences in cytokine profile as well as in TCR Vbeta usage.


Subject(s)
Antigens, Viral/immunology , CD4-Positive T-Lymphocytes/immunology , Murine hepatitis virus/immunology , T-Lymphocytes, Helper-Inducer/immunology , Viral Envelope Proteins/immunology , Animals , Epitope Mapping , Mice , Murine hepatitis virus/metabolism , T-Lymphocyte Subsets/immunology
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