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Biomedical subjects

R A Rudick

Publications and source records attributed to R A Rudick.

At least 73 records · Page 4Linked to original sources
PubMed1995

Biologic effects of interferons: relevance to multiple sclerosis.

Recombinant interferon beta has established efficacy for relapsing-remitting MS, but the mechanisms of action in the disease are not well understood. Interferons (IFNs) mediate biologic effects by receptor-mediated gene activation. Binding by IFNs to high-affinity surface receptors results in physophorylation and activation of two cytoplasmic tyrosine kinases. This leads to activation of latent transcription factors in cell cytoplasm that translocate to the nucleus, where activated transcriptional elements interact with the interferon-stimulated response element (ISRE), leading to transcription of the interferon-stimulated genes (ISGs). IFN's biologic effects are mediated by function of the ISGs. The biologic effects of IFNs have been classified as antiviral, antiproliferative and immunomodulatory; effects are complex, however, because there are two separate types of IFN, four separate varieties of type I IFN and approximately 30 known interferon-regulated genes. Known effects of IFN that may plausibly relate to therapy efficacy in MS are discussed.

Antineoplastic Agents↗
PubMed1994

Advances in specific therapy for multiple sclerosis.

During the past year, two new agents have been demonstrated to be of value in multiple sclerosis. The first agent, a form of recombinant interferon beta (Betaseron; Berlex Labs, Cedar Knolls, NJ), is effective in reducing relapses and also prevent accumulation of brain lesions over time, but has no demonstrated effect on the accumulation of disability over time. The second agent, methylprednisolone (Solumedrol; The Upjohn Co., Kalamozoo, MI), administered in megadose pulses over several days and followed by an oral prednisone taper, reduces the conversion rate of patients with optic neuritis to multiple sclerosis by approximately 50% over 2 years compared with placebo or oral prednisone alone. The mechanisms by which these agents exert their benefits are incompletely understood, but both have complex, relatively widespread effects on the immune systems. The demonstration of efficacy for both of these agents represent landmarks in the search for an effective treatment for multiple sclerosis; both agents seem to provide prophylaxis against future relapses, and methylprednisolone seems to delay the development of the disease. Their introduction into the clinical environment will undoubtedly have a profound effect on the day-to-day care of multiple sclerosis patients as well as the designs of future basic and clinical research. Other new therapies that have substantial potential for benefit in multiple sclerosis but require further definitive study include intramuscular copolymer 1 for relapsing disease and low-dose oral methotrexate and booster doses of intravenous cyclophosphamide for chronic progressive disease.

Adrenal Cortex Hormones↗
PubMed1993

In vitro and in vivo inhibition of mitogen-driven T-cell activation by recombinant interferon beta.

Recombinant interferon beta (rIFN beta) is being tested as experimental immunotherapy for exacerbating-remitting MS. To clarify the possible mechanisms of a therapeutic response to rIFN beta in MS patients, we conducted studies on the effects of rIFN beta on mitogen-driven T-cell activation by stimulating peripheral blood mononuclear cells (PBMC) with concanavalin A (ConA) or with anti-CD3 monoclonal antibodies in the presence or absence of rIFN beta. We monitored T-cell activation using proliferation assays or by expression of surface activation markers detected by flow cytometry. In vitro rIFN beta, in concentrations > or = 10 U/ml, inhibited PBMC proliferation or surface expression of interleukin-2 receptor (IL-2R), transferrin receptor, or CD2. In contrast, rIFN gamma augmented mitogen-driven IL-2R expression. PBMC isolated from normal volunteers or MS patients responded to ConA and rIFN beta in a similar manner. We conducted pilot in vivo studies in exacerbating-remitting MS patients participating in a double-blind placebo-controlled clinical trial of rIFN beta. PBMC were isolated from study participants immediately before and 24 hours after a weekly study injection. IL-2R expression by T cells was determined following a ConA stimulus. While there was no significant change following placebo injection, rIFN beta recipients showed significantly reduced ConA-driven IL-2R expression following study injection. The results document in vitro and in vivo inhibition of mitogen-driven T-cell activation by rIFN beta. This suggests a possible mechanism underlying a therapeutic response to rIFN beta in MS patients.

Antibodies, Monoclonal↗
PubMed1992

Low-dose (7.5 mg) oral methotrexate for chronic progressive multiple sclerosis. Design of a randomized, placebo-controlled trial with sample size benefits from a composite outcome variable including preliminary data on toxicity.

OBJECTIVE: To present a detailed description of (1) the study design of this ongoing trial, (2) advantages of using a composite outcome variable instead of multiple individual outcome measures, (3) treatment group characteristics at baseline, and (4) observed short-term methotrexate (MTX) toxicity. DESIGN: Randomized, double-masked, placebo-controlled intervention study. SETTING: Referral-based outpatient multidisciplinary multiple sclerosis (MS) clinic. PATIENTS: Participation offered to all clinically definite chronic progressive multiple sclerosis (CPMS) patients attending clinic ages 21 to 60, disease duration > 1 year, Expanded Disability Status Scale (EDSS) score 3.0 to 6.5 (ambulatory with moderate disability). Patients first stratified by EDSS 3.0 to 5.5 and 6.0 to 6.5, then randomized to MTX or placebo treatment. INTERVENTION: Weekly oral low-dose (7.5 mg) MTX or identical-appearing placebo for 2 years followed by a 1-year observation period. MAIN OUTCOME MEASURES: Sample size calculations undertaken prior to enrolling patients based upon a composite outcome variable consisting of designated change in any of the following functional measures: (1) EDSS, (2) Ambulation Index (AI), (3) Box and Block Test (BBT), and (4) 9-Hole Peg Test (9HPT). RESULTS: (1) Treatment group characteristics were comparable at baseline, (2) no patient has been withdrawn for adverse effects or lost to follow-up, (3) no significant short-term MTX toxicity has been observed. CONCLUSIONS: (1) The use of a composite outcome measure in the design of MS clinical trials is a promising alternative to multiple individual outcome measures that are relatively insensitive to detecting clinical change, (2) low-dose oral weekly MTX does not appear to be associated with significant short-term toxicity in CPMS. Conclusions regarding therapeutic efficacy of MTX in MS must await completion of this clinical trial.

Adult↗
PubMed1992

Magnetic resonance imaging lesion enlargement in multiple sclerosis. Disease-related activity, chance occurrence, or measurement artifact?

Magnetic resonance imaging (MRI) may demonstrate disease activity in a number of ways in patients with multiple sclerosis. Newly appearing MRI lesions, gadolinium-enhancing lesions, and enlargement of preexisting lesions are frequently taken as evidence of disease activity. Furthermore, serial MRI studies have been stated to be more sensitive than repeated neurologic examinations in detecting disease activity. We assessed the validity of using lesion enlargement as a measure of disease activity by repeatedly measuring the area of all MRI lesions in four patients with multiple sclerosis. The size-frequency distribution in all patients was similar, with 80% of the lesions measuring less than 0.67 cm2. The median coefficient of variation for three successive lesion measurements was inversely related to lesion area, ranging from 22.6% for the more common smaller lesions (less than 0.67 cm2) to 12.1% for larger lesions. Based on these coefficients of variation, a change in a particular lesion exceeding 45.2% for a baseline lesion smaller than 0.67 cm2 and 24.2% for a baseline lesion greater than or equal to 0.67 cm2 should be required to exclude a change due to measurement variability. It remains necessary to determine the number of lesions that must change when multiple lesions are present in the baseline MRI to reliably exclude chance occurrence when establishing MRI-evident disease activity. Guidelines for determining these criteria are presented, as are the limitations inherent in the statistical model employed to make these determinations.

Humans↗
PubMed1992

Cytokine secretion by multiple sclerosis monocytes. Relationship to disease activity.

Autoantigen recognition by specific T cells may initiate a tissue-specific immune response in multiple sclerosis (MS), which is a chronic inflammatory demyelinating disorder. During subsequent nonspecific immune amplification, interleukin 1 beta and tumor necrosis factor alpha are released by cells of the monocyte/macrophage lineage, with the potential to influence profoundly immune regulation systemically or within the central nervous system. Regulation of monocyte inflammatory gene expression may be relevant to the pathogenesis of MS. We investigated spontaneous secretion of interleukin 1 beta, tumor necrosis factor alpha, and prostaglandin E2 with the use of monocytes that we isolated from patients with active (n = 9) and stable (n = 9) MS and from age-matched normal controls (n = 9). The patient groups with MS were matched for age, duration of MS, and disease severity. Patients with active disease were within weeks of the onset of a clinical exacerbation. Monocytes were isolated by density gradient centrifugation, followed by adherence to plastic tissue culture flasks, resulting in a highly purified adherent monocyte preparation. Monocytes from patients with active disease spontaneously secreted less tumor necrosis factor alpha and less prostaglandin E2 compared with that in patients with stable MS, while interleukin 1 beta levels were below the level of assay sensitivity. Levels of interleukin 1 beta and tumor necrosis factor alpha increased to similar levels in response to lipopolysaccharide (0.1 mg/L), indicating that altered cell viability could not account for the observed differences. In response to lipopolysaccharide, prostaglandin E2 levels increased more significantly in patients with stable than active MS, suggesting differential sensitivity to stimuli of arachidonic acid metabolism.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Quality of life in multiple sclerosis. Comparison with inflammatory bowel disease and rheumatoid arthritis.

Multiple sclerosis (MS) and other chronic illnesses can drastically decrease quality of life (QOL), but there has been little systematic study of QOL in patients with chronic medical diseases. We analyzed QOL in 68 patients with MS, 164 patients with inflammatory bowel disease, and 75 patients with rheumatoid arthritis. The previously validated test instrument was a standardized interview consisting of 41 questions clustered in four subscales: functional and economic scale, social and recreational scale, affect and life in general scale, and medical problems scale. Patients were included in the study if they had a definite medical diagnosis and disease duration of 10 years or longer. In the patients with MS, Kurtzke's Expanded Disability Status Scale correlated strongly only with the medical problems score. Of Kurtzke's Functional System Scales, only the visual Functional System Scores was correlated with total QOL and subscale scores, suggesting that vision is strongly related to QOL. Duration of MS was unrelated to QOL scores. There were significant differences between patients with MS, inflammatory bowel disease, and rheumatoid arthritis on the subscale and total QOL scores. Results suggested that QOL was best in the inflammatory bowel disease group and worst in the MS group. Numerous statistically significant differences on individual questions were evident, suggesting that unique clinical profiles differentially characterize these diseases. Assessments of QOL are a meaningful addition to impairment scales, such as Kurtzke's Expanded Disability Status Scale. Furthermore, QOL scores may meaningfully measure the impact of a chronic medical disease, such as MS, compare the impacts of different diseases, and assess the effects of therapeutic intervention.

Activities of Daily Living↗
PubMed1992

Monocytes in active multiple sclerosis: intact regulation of HLA-DR density in vitro despite decreased HLA-DR density in vivo.

HLA-DR expression on circulating monocytes varies as a function of disease activity in patients with multiple sclerosis (MS), a putative immunopathological demyelinating disorder. Specifically, monocytes isolated from subjects with active MS exhibit reduced HLA-DR antigen density, and immunoregulatory aberrations such as impaired T lymphocyte-mediated suppression correlate strongly with this quantitative defect. To address the mechanism underlying this phenomenon, we compared in vitro regulation of HLA-DR by interferon beta (IFN beta), interferon gamma (IFN gamma), and lipopolysaccharide (LPS) in monocytes from patients with stable and active MS and normal individuals. Interferon-gamma and LPS enhanced monocyte expression of HLA-DR equally in both MS patient groups, suggesting that underexpression of HLA-DR in active MS was not explained by impaired in vivo monocyte responsiveness. Furthermore, interferon regulation of HLA-DR in normals and stable MS subjects was indistinguishable, indicating that aberrant interferon-mediated regulation of class II major histocompatibility complex (MHC) on circulating monocytes does not appear to be a characteristic of the MS disease state.

HLA-DR Antigens↗
PubMed1991

Diagnostic criteria for multiple sclerosis research involving multiply affected families.

Existing diagnostic criteria for multiple sclerosis present significant limitations when assessing multiplex families for three reasons: (1) restricting age of onset to 10 to 50 years is likely to exclude 10% of patients known to have a later onset, (2) diagnoses based on subjective information can potentially result in a false-positive diagnosis, and (3) including progressive myelopathies occurring within families, particularly when highly symmetrical, may result in the improper inclusion of genetically determined neurological diseases such as familial spastic paraparesis. The validity of any molecular genetic approach for determining disease susceptibility critically depends on diagnostic accuracy. We present adapted diagnostic criteria that address each of these diagnostic pitfalls unique to multiplex multiple sclerosis family research.

Family↗
PubMed1991

Sensitive competitive-binding ELISAs for quantifying free kappa and lambda light chains in cerebrospinal fluid.

Simple, sensitive, and fully standardized solid-phase enzyme-linked competitive binding immunoassays to quantify free kappa and lambda immunoglobulin light chains are described. The assays were developed to measure the concentration of free light chains in cerebrospinal fluid (CSF), in part because elevated levels of free kappa light chains have utility as a diagnostic marker for multiple sclerosis (MS). Polyclonal rabbit antibodies raised against pooled Bence Jones proteins are bound to solid-phase Staphylococcal protein A and used as the primary antisera in this assay. A pool of Bence Jones proteins isolated from the urine of 10 individuals with multiple myeloma are used as a biotin-labeled ligand and to develop a standard curve. The assays as described are sensitive to the low nanogram range and are specific for free kappa or lambda light chains. The assays were found to have acceptable precision, and results correlated highly with concentrations determined using competitive-binding radioimmunoassays previously described.

Binding, Competitive↗
PubMed1991

Interferon-beta specifically inhibits interferon-gamma-induced class II major histocompatibility complex gene transcription in a human astrocytoma cell line.

We established cultures of human astrocytes and astrocytoma cells from surgical specimens, to study regulation of class II major histocompatibility (MHC) complex antigen expression by interferons. Using these cultures we previously showed that expression of the class II MHC determinant HLA-DR could be induced by interferon-gamma and this induction was inhibited by interferon-beta. In this report, we extend these observations by showing that the inhibitory effect of interferon-beta on interferon-gamma induction of the class II MHC gene HLA-DR alpha was exerted at the transcriptional level, as documented by nuclear run-on experiments and confirmed with blot hybridization analysis. Astrocyte expression of intercellular adhesion molecule-1 (ICAM-1) was induced efficiently by interferon-gamma, but not by interferon-beta, and induction of ICAM-1 expression by interferon-gamma could not be impaired by interferon-beta, suggesting that the suppressive effect on induction of HLA-DR was relatively gene-specific. Furthermore, interferon-beta did not antagonize interferon-gamma induction of HLA-DR expression in human monocytes, suggesting that the inhibition observed in astrocytes was relatively tissue-specific.

Astrocytes↗
PubMed1990

The clinical course of multiple sclerosis during pregnancy and the puerperium.

Eight women with multiple sclerosis were followed up through pregnancy. Clinical conditions, T-cell subsets, and levels of immunoactive pregnancy-associated proteins were measured twice during the pregnancy and twice during the first postpartum year. None of the women's conditions worsened during pregnancy, although one woman reported a slight increase of symptoms. Six of the eight women experienced relapses within the first 7 weeks after delivery. The number and percent of CD8 suppressor T cells were lower, and the CD4 helper-CD8 suppressor T-cell ratio was higher in the pregnant patients with multiple sclerosis compared with pregnant control women throughout pregnancy and the first 6 months post partum. There was no evident relationship between these parameters and clinical disease activity. Levels of alpha-fetoprotein, alpha 2-pregnancy-associated glycoprotein, and pregnancy-associated plasma protein A, all immunosuppressive proteins associated with pregnancy, were not significantly different in pregnant patients with multiple sclerosis and pregnant controls without multiple sclerosis. The study suggested that the risk of clinical relapse after delivery may be higher than has been reported previously. Furthermore, although there were differences in suppressor T cells, they were not predictably linked to changes in clinical disease activity.

Adult↗