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Biomedical subjects

A T Reder

Publications and source records attributed to A T Reder.

At least 19 recordsLinked to original sources
PubMed2004

Abnormal levels of interferon-gamma receptors in active multiple sclerosis are normalized by IFN-beta therapy: implications for control of apoptosis.

Interferon-gamma is produced by immune cells before MS exacerbations, and exogenous IFN-gamma treatment causes MS attacks. IFN-beta production, conversely, rises after exacerbations. IFN-beta therapy ameliorates MS, possibly by lowering IFN-gamma secretion and inhibiting responses to IFN-gamma. IFN-gamma effects are regulated by IFN-gamma receptor (IFNGR) expression. IFN-gamma is pro-inflammatory at low IFNGR levels, but induces apoptosis in cells with high IFNGR levels. We studied effects of IFN-beta1a therapy on IFNGR expression on PMA/ionomycin-stimulated PBMNC's in 29 patients with active and stable MS. Surface IFNGR-alpha (the binding chain) and IFNGR-beta (signaling chain), as well as intracellular IFN-gamma and IL-10, were measured with flow cytometry. Before IFN-beta therapy, intracellular IL-10 was depressed and the IFN-gamma/IL-10 ratio was elevated in MS, particularly during clinical activity. With IFN-beta therapy IL-10 levels increased, suggesting that a Th2 deficit was reversed. The IFNGR-alpha chain was significantly elevated on lymphocytes in stable and active MS patients not receiving IFN-beta therapy. Expression of the IFNGR-beta chain was low during active untreated disease. After IFN-beta therapy, the IFNGR-beta/alpha ratio increased at 3 months and fell at 12 months. Increased susceptibility to apoptosis with high IFNGR-beta chain expression at 3 months is likely to remove activated T cells during IFN-beta therapy.

Adult↗
PubMed2003

Psychometric evaluation of the Chicago Multiscale Depression Inventory in multiple sclerosis patients.

OBJECTIVE: The Chicago Multiscale Depression Inventory (CMDI), a comprehensive self-report measure of depression, has proven useful in the assessment of patients with chronic medical conditions. The objective of this study was to determine the validity of the CMDI in multiple sclerosis (MS) patients and explore the nature of depressive symptoms reported by people with MS. METHOD: Using a combined classical and modern psychometric approach, the factor structure of responses in MS patients was compared with that of a normative sample to confirm meaningful subtypes of depression in MS (mood, depressive cognition, and vegetative symptoms). Patient groups also were compared by disease severity to evaluate differences in depression associated with differences in disease severity. RESULTS: The results supported the factor structures of the measure, which was internally consistent, reliable, and factorially valid. Some items function differently in MS patients when compared with depressed patients and normals, offering a further opportunity to understand the unique clinical aspects of depression in people with MS compared with those without a concurrent physical illness. CONCLUSIONS: Use of the CMDI to assess separate dimensions of depression may help to clarify the complex interrelationships among aspects of depression and health-related behavior.

Adult↗
PubMed1998

Effects of an anti-IL-10 monoclonal antibody on rIFNbeta-1b-mediated immune modulation. Relevance to multiple sclerosis.

The mechanism of action of recombinant IFNbeta1b (IFNbeta-1b), as a therapy for multiple sclerosis (MS), is still unknown but may result from the enhancement of ConA-induced suppressor cell function and the inhibition of IFNgamma secretion by lymphocytes. We previously demonstrated that IFNbeta-1b stimulated modest amounts of IL-10 secretion by monocytes and IL-10 activity, as cytokine synthesis inhibitory factor, was normal in MS. To determine whether IL-10 plays a role in IFNbeta-1b modulation of immune function in MS, we studied ConA-induced suppressor cell function and IFNgamma production in presence of IFNbeta-1b and an anti-IL-10 monoclonal antibody (mAb). Anti-IL-10 mAb significantly reduced the effect of IFNbeta-1b on ConA-induced suppressor cell function and IFNgamma production in healthy subjects; MS patients showed a trend of inhibition. We hypothesized that IL-10 may play a role in mediating the effects of IFNbeta-1b on suppressor cell function and IFNgamma production but suppressor molecules other than IL-10 could be also involved.

Adult↗
PubMed1998

Monocyte activation in multiple sclerosis.

Monocytes, macrophages, and microglia have a central role in the CNS inflammation of MS. Monocytes are important in the earliest events in MS. Peripheral blood monocytes secrete prostaglandins before MS attacks. During clinical activity monocyte activation markers increase and IL-1 and TNF-alpha levels are elevated. Other monocyte products such as IL-10 reduce inflammation. IL-10 mRNA in MNC is increased during stable disease. Manipulation of monokine secretion and expression of monocyte surface proteins are reasonable approaches for immune therapy of MS.

Animals↗
PubMed1997

Increased CD80(+) B cells in active multiple sclerosis and reversal by interferon beta-1b therapy.

Costimulatory molecules help determine T cell responses. CD80 (B7-1) and CD86 (B7-2), costimulatory proteins on antigen-presenting cells, bind to CD28 on T cells. When costimulation is coupled with a signal through the T cell receptor (TCR), T cell proliferation and cytokine secretion are induced. However, TCR signaling without CD80/CD86CD28 costimulation causes anergy. During multiple sclerosis (MS) exacerbations, circulating immune cells are activated, Th1 cytokine levels in the blood are elevated, and blood-derived immune cells destroy brain oligodendroglia. In the experimental autoimmune encephalomyelitis model of MS, CD80 on antigen-presenting cells induces Th1 cell responses; CD86 enhances generation of Th2 cells. Variation in CD80 and CD86 expression is likely to influence immune regulation in MS. We demonstrate that the number of circulating CD80(+) lymphocytes is increased significantly during MS exacerbations, but is normal in stable MS. These CD80(+) lymphocytes are predominantly B cells, based on two-color flow cytometry. The number of CD71(+) and HLA-DR+ lymphocytes and monocytes is also increased in active MS. Therapy with IFN beta-1b markedly reduces the number of circulating CD80(+) B cells and increases CD86(+) monocyte number. HLA-DR+, CD71(+), and CD25(+) mononuclear cell numbers are also reduced by therapy. The number of CD80(+) cells may be a useful surrogate marker during IFN-beta therapy, and reduction of CD80-mediated costimulation may be one therapeutic mechanism by which IFN-beta acts in MS.

Adjuvants, Immunologic↗
PubMed1996

The mast cells of the multiple sclerosis brain.

Traditional staining methods, plus indirect immunoperoxidase techniques for IgE and mast cell tryptase (MCTr) were used to study the mast cells (MCs) of multiple sclerosis (MS) and normal brains. The MCs varied in number in MS amongst perivascular inflammatory cells as well as free in the parenchyma, especially inside and around "chronic active' plaques. Since MCs do not migrate, and rarely divide in maturity, they must have developed locally. Staining for IgE was moderately strong on and within MCs, and weak within some plasma cells. MCTr reacted strongly both within CNS and outside it. Being a strong neutral proteinase. MCTr, plus IgE, could conceivably have played some role in the pathogenesis of the MS plaques.

Brain↗
PubMed1996

Interferon beta-1b effects on cytokine mRNA in peripheral mononuclear cells in multiple sclerosis.

IFN-beta reduces the number and severity of exacerbations of multiple sclerosis (MS), presumably by modifying immune regulation. We used semiquantitative polymerase chain reaction (RT-PCR) to measure mRNA levels for cytokines before and after IFN beta-1b therapy. mRNA was extracted from mononuclear cells of nine healthy controls and 31 patients with MS. Before therapy, IL-10 and leukemia inhibitory factor (LIF) mRNA levels were elevated in stable MS compared to active MS. Twenty four hours after IFN beta-1b treatment, mRNA levels for IL-1, IL-2, IL-4, IL-6, IL-10, IL-12, IL-13, IFN-gamma, TNF-alpha and LIF had not changed. At 1 week, TNF-alpha mRNA increased and IL-10 and LIF mRNA rose in 75% of patients. IL-2, IL-4, IL-12, IL-13 and IFN-gamma did not change. At 3 months, cytokine mRNA returned to baseline levels. mRNA for the IFN-induced antiviral enzyme, 2,5-OAS, rose by 24 h, peaked at 1 week, and remained elevated thereafter. Serum triglycerides and liver enzymes rose after therapy. Increased SGPT at 3 months correlated with TNF-alpha mRNA levels, suggesting that cytokines may cause some side effects of IFN beta-1b. Baseline cytokine mRNA levels reflect disease activity, but the therapeutic effect of IFN beta-1 b does not appear to be explained by changes in cytokine mRNA levels.

2',5'-Oligoadenylate Synthetase↗
PubMed1996

Improved delayed visual reproduction test performance in multiple sclerosis patients receiving interferon beta-1b.

We assessed neuropsychological function longitudinally in 30 MS patients who participated in the pivotal trial of interferon beta-1b (IFN-beta-1b). Nine patients received high-dose IFN-beta-1b (8.0 million units), eight low-dose IFN-beta-1b (1.6 MIU), and 13 placebo. There was significant improvement in Wechsler Memory Scale Visual Reproduction-Delayed Recall scores between years 2 and 4 of the trial in MS subjects receiving high-dose IFN-beta-1b. Motoric performance, MRI lesion area, and depression rating scores did not correlate with this finding. Comparison of MRI at baseline and at years 2 and 4 revealed significant changes over time for the total cohort (p < 0.02). Mean lesion area in the high-dose group did not change over time, whereas the low-dose and placebo groups had increases in total lesion area of 28 and 36%, respectively, at year 4. Expanded disability status scale scores did not change significantly between years 2 and 4 of the trial, nor did they correlate with MRI lesion area at any assessment point. We conclude that high-dose IFN-beta-1b improves delayed visual reproduction test performance in MS patients, a finding unlikely to be explained by practice effects or brain lesion area.

Adult↗
PubMed1995

Urinary myelin basic protein-like material as a correlate of the progression of multiple sclerosis.

In the multicenter, randomized, placebo-controlled trial of alternate-day injections of recombinant interferon beta-1b in relapsing-remitting multiple sclerosis (MS), urine specimens were collected periodically from all patients (n = 64) in two of the clinical test sites over the 2 years of the study. Urine specimens were also collected over two consecutive 24-hour periods from 43 patients from a third center. Urine samples were assayed for their content of myelin basic protein-like material (MBPLM), the level of which was correlated with clinical changes, cranial magnetic resonance imaging results, and the development of progressive disease. Concordant changes in creatinine values affected some of the relationships of MBPLM. The level of urinary MBPLM correlated with a chronic progressive course and with the number of lesions and the total lesion area on cranial magnetic resonance images. A rise in the level of urinary MBPLM appeared to antedate the clinical transition from a relapsing-remitting to a chronic progressive course. By chance, the randomized entry of patients led to significant differences in urinary MBPLM levels among the three treatment groups, thus precluding correlation studies of treatment effects. However, the patient group from which 24-hour specimens were collected showed that the patients with relapsing-remitting MS changing to a chronic progressive course, and more specifically, those patients with chronic progressive MS receiving placebo, had the highest values of urinary MBPLM. These findings indicate that urinary MBPLM may offer an objective test and possibly serve as a surrogate marker for detecting or predicting the failure of remission or the transition to a progressive phase of MS.

Analysis of Variance↗
PubMed1995

Interferon effects on interleukin-10 secretion. Mononuclear cell response to interleukin-10 is normal in multiple sclerosis patients.

The mechanism of action of recombinant interferon beta 1b (rIFN beta 1b/IFN beta-1b), the approved therapy for multiple sclerosis (MS), is still unclear. Here we present evidence that part of the therapeutic effects of rIFN beta 1b in MS might result from the induction of the secretion of interleukin (IL)-10, a cytokine previously designated cytokine synthesis inhibitory factor (CSIF). We observed that rIFN beta 1b stimulated significant IL-10 secretion by monocytes from MS patients after brief incubation (18 h), whereas rIFN gamma, an inducer of MS exacerbations, was unable to stimulate IL-10 production in similar conditions. To determine the role of IL-10 as CSIF in the disease, we have also investigated its effects on TNF alpha and IL-6 secretion by peripheral blood mononuclear cells from MS patients. Recombinant human IL-10 significantly inhibited tumor necrosis factor alpha and IL-6 secretion induced by rIFN gamma, lipopolysaccharide (LPS), and rIFN gamma + LPS in MS patients and in control subjects. The induction of IL-10 secretion by rIFN beta 1b and the IL-10 inhibitory activity on pro-inflammatory cytokine secretion induced by rIFN gamma in MS make this cytokine a potential candidate to treat the disease.

Cells, Cultured↗
PubMed1995

Clinical and genetic studies of fatal familial insomnia.

We report a 42-year-old man who, for 8 months, had intermittent motor abnormalities and mild difficulty falling asleep. A diagnosis of fatal familial insomnia (FFI) became evident over the next 6 months when he developed progressive insomnia, myoclonus, sympathetic hyperactivity, and dementia. The amyloid or prion protein (PrP) genotype showed features typically seen in FFI, with a 178Asn mutation and a 129Met polymorphism. There was also a deletion of one octapeptide repeat, suggesting that the association of 178Asn mutation with the 129Met polymorphism is not due to "founder effect." Western immunoblot showed a trace of protease-resistant PrP in the thalamus--which had the most significant neuronal loss and gliosis--a moderate amount of PrP in the fronto-temporal area, and no detectable protein elsewhere in the brain. Endocrine studies showed that a circadian modulation of hormonal levels could be maintained despite a near-total absence of sleep. Administration of gamma-hydroxybutyrate induced a remarkable increase in slow-wave sleep.

Adult↗
PubMed1994

Adrenal size is increased in multiple sclerosis.

OBJECTIVE: To determine if adrenal glands are enlarged in multiple sclerosis (MS). Patients with MS and major depression are insensitive to glucocorticoid feedback regulation. Depressed patients have excessively high glucocorticoid levels and enlarged adrenal glands. To our knowledge, this is the first study of adrenal size in MS. Chronic high levels of adrenal glucocorticoid in MS may downregulate responses to exogenous or endogenous steroids. DESIGN: Retrospective postmortem analysis compared adrenal size in MS with that in other neurologic and non-neurologic diseases. SETTING: Autopsy cases were obtained from the records of a tertiary care hospital. PATIENTS: Ten patients had definite MS; 13, amyotrophic lateral sclerosis; and 14, acute myocardial infarction. MAIN OUTCOME MEASURES: Adrenal and body weight at autopsy. RESULTS: At postmortem examination, the adrenal glands of patients with MS were enlarged in comparison with the adrenal glands of patients who died of acute myocardial infarction or amyotrophic lateral sclerosis. The adrenal glands of the patients with MS were 36% larger than those of the patients with amyotrophic lateral sclerosis who had comparable body weights. The adrenal-body weight ratio was 40% greater in patients with MS than in patients who died of acute myocardial infarction. CONCLUSIONS: The increased adrenal size in patients with MS may allow excessive glucocorticoid secretion in response to stress and affect immune regulation.

Adrenal Glands↗
PubMed1994

IFN-gamma, IFN-beta, and PGE1 affect monokine secretion: relevance to monocyte activation in multiple sclerosis.

Activated antigen-presenting cells and central nervous system microglia produce IL-1 beta, TNF-alpha, IL-6, and PGE-1. These monokines participate in the lymphocyte activation, demyelination, and intrathecal immunoglobulin synthesis seen in multiple sclerosis (MS). Exacerbations of MS are ameliorated by IFN-beta, but provoked by IFN-gamma, possibly through an effect on monocytes (Mo). We studied the effects of IFNs and PG on monokine secretion under stringent low-endotoxin conditions. Spontaneous and IFN-gamma-induced IL-1 beta secretion was greater in MS than in NL Mo. IFN-beta did not inhibit IFN-gamma-induced secretion of monokines, which contrasts with IFN-beta's inhibitory effect on IFN-gamma-induced MHC class II expression. PGE1, a cAMP agonist, caused a 30-fold induction of IL-6 secretion. Indomethacin directly inhibited this induction. Low-dose IFN-beta, through effects on T cells, and cAMP agonists, through effects in T cells and Mo, may ameliorate inflammatory diseases characterized by excessive monokine secretion.

Alprostadil↗
PubMed1994

Prostaglandins and inhibitors of arachidonate metabolism suppress experimental allergic encephalomyelitis.

Experimental allergic encephalomyelitis (EAE) is an autoimmune inflammatory disease of the central nervous system (CNS). It is an animal model of post-infectious encephalomyelitis and multiple sclerosis (MS). Acute EAE is mediated by macrophages and by T helper 1 (Th1) lymphocytes directed against brain antigens. Inflammation in EAE could potentially be modified by prostaglandins (PG) secreted by blood monocytes (Mo) and brain glial cells. PGE elevates cAMP, which inhibits Mo function and selectively blocks secretion of cytokines by Th1 cells. In the present study, we found that a long-acting PGE1 analogue (LAPGE) inhibited clinical and histological EAE. Indomethacin (INDO) also suppressed active EAE. The combination of INDO plus LAPGE inhibited disease further, possibly by allowing LAPGE to function unopposed by immunostimulatory PG. EAE was suppressed when these agents were administered from the time of immunization or from the onset of clinical disease. The combination of INDO plus LAPGE also inhibited delayed-type hypersensitivity (DTH) reactions to myelin basic protein (MBP), and diminished in vitro lymphocyte responses to mitogens and MBP. PGE analogues and modifiers of arachidonate metabolism block autoimmune responses to brain antigens in vitro and in vivo, and may ameliorate inflammatory and autoimmune diseases of the brain and other organs.

Alprostadil↗