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Biomedical subjects

R M Silver

Publications and source records attributed to R M Silver.

At least 37 records · Page 2Linked to original sources
PubMed1999

Assessment and management of scleroderma lung disease.

Lung disease is a major cause of morbidity and is the leading cause of mortality in patients with systemic sclerosis, most commonly occurring as interstitial lung disease or as pulmonary hypertension. Cyclophosphamide has been used to treat the interstitial lung disease and a placebo-controlled trial is planned. Potent pulmonary vasodilators, many of which have been studied in primary pulmonary hypertension, are now undergoing study in patients with systemic sclerosis.

Humans↗
PubMed1999

Solvent oriented hobbies and the risk of systemic sclerosis.

OBJECTIVE: To examine whether those participating in solvent oriented hobbies (SOH) are at greater risk of developing systemic sclerosis (SSc), and if the association is modified by the presence of the anti-Scl70 antibody. METHODS: Patients with SSc and controls were recruited from a university hospital rheumatology clinic. Recreational hobby and occupational histories were obtained along with blood samples. Cumulative scores were created for participation in SOH. Logistic regression was used to calculate odds ratios associated with SOH exposure after adjustment for sex, age at diagnosis, and occupational solvent exposure, and to examine the association between SOH exposure and the presence of anti-Scl70. RESULTS: Solvent exposure based on hobbies and occupations was determined for 178 cases (141 women, 37 men) and 200 controls (138 women, 62 men). Overall participation in SOH was not associated with SSc. However, odds of high cumulative SOH exposure was 3 times greater in those patients with SSc testing positive for the anti-Scl70 antibody compared to patients testing negative (OR 2.9, 95% CI 1.1, 7.9), and twice as great as controls (OR 2.5, 95% CI 1.1, 5.9). CONCLUSION: While patients with SSc did not participate more often in SOH than controls over all, odds of high cumulative SOH exposure was greater among patients with SSc testing positive for anti-Scl70 compared to those testing negative and compared to controls. These results provide further evidence that environmental agents may play a role in the development of Ssc.

Female↗
PubMed1998

Is occupational organic solvent exposure a risk factor for scleroderma?

OBJECTIVE: The primary objective was to determine whether occupational exposure to organic solvents is related to an increased risk of systemic sclerosis (SSc; scleroderma). METHODS: Occupational histories were obtained from 178 SSc patients and 200 controls. Exposure scores were computed for each individual using job exposure matrices, which were validated by an industrial expert. RESULTS: Among men, those with SSc were more likely than controls to have a high cumulative intensity score (odds ratio [OR] 2.9, 95% confidence interval [95% CI] 1.1-7.6) and a high maximum intensity score (OR 2.9, 95% CI 1.2-7.1) for any solvent exposure. They were also more likely than controls to have a high maximum intensity score for trichloroethylene exposure (OR 3.3, 95% CI 1.0-10.3). Among men and women, significant solvent-disease associations were observed among SSc patients who tested positive for the anti-Scl-70 autoantibody; these trends were not observed among the men and women who tested negative for anti-Scl-70. CONCLUSION: These results provide evidence that occupational solvent exposure may be associated with an increased risk of SSc.

Adult↗
PubMed1998

Effect of antiphospholipid antibodies on beta(2) glycoprotein I-phospholipid Interaction.

PROBLEM: Beta(2)glycoprotein I (beta(2)GPI) physiologically binds to negatively charged phospholipids (PLs) and is a natural regulator of the coagulation cascade. Thrombotic clinical complications and recurrent fetal loss associated with autoimmune antiphospholipid (aPL) antibodies are thought to be related to their binding to Beta(2)GPI-PL complex and interference with the physiological function of Beta(2)GPI. METHOD OF STUDY: To investigate the effect of aPL on beta(2)GPI-PL interaction, we studied the binding of biotinylated Beta(2)GPI to cardiolipin (CL) by enzyme-linked immunosorbent assay (ELISA) in the presence and absence of purified aPL immunoglobulin G (IgG) antibodies. RESULTS: Adding five different aPL IgG antibodies with different levels of aPL activity isolated from the sera of five patients with aPL-associated recurrent fetal death greatly increased the binding of biotinylated beta(2)GPI to CL-coated plates. The optical densities (ODs) were 0.635, 0.890, and 1.265 in the presence of three aPL IgG antibodies, compared to 0.425 in the absence of aPL IgG. In contrast, normal human IgG had no enhancing effect. The OD was 0.480 and 0.425, respectively. The enhancement of beta(2)GPI binding to CL by aPL IgG correlated with the titers of aPL antibodies. The use of phosphate-buffered saline with increasing salt concentrations as a washing buffer for the ELISA resulted in more stable binding of beta(2)GPI to PL in the presence of aPL IgG. CONCLUSIONS: These findings suggest that the binding of autoimmune aPL antibodies to beta(2)GPI-PL complex results in abnormally tighter interaction between beta(2)GPI and PLs, which may lead to physiological dysfunction of beta(2)GPI as a regulator of coagulation.

Antibodies, Antiphospholipid↗
PubMed1997

Cytokine concentrations in bronchoalveolar lavage fluid of patients with systemic sclerosis.

OBJECTIVE: The pathophysiology of pulmonary fibrosis in patients with systemic sclerosis (SSc) is poorly understood, but a number of recent studies have demonstrated an inflammatory process involving the lower respiratory tract. The objective of the present study was to determine the concentrations of several cytokines in the bronchoalveolar lavage (BAL) fluid of patients with SSc and to assess whether the enhanced expression of certain cytokines is associated with the presence of alveolitis. METHODS: BAL was performed on patients with SSc (with or without alveolitis) and on normal control subjects. Lyophilized BAL fluid samples were assayed by enzyme-linked immunosorbent assay for tumor necrosis factor alpha (TNF alpha), interleukin-1alpha (IL-1alpha), IL-4, IL-6, IL-8, macrophage inflammatory protein 1alpha (MIP-1alpha), and RANTES. RESULTS: There were significant differences between groups in the BAL fluid concentrations of TNF alpha (P = 0.0005, with levels in SSc patients with alveolitis higher than those in normal controls), IL-8 (P = 0.006, with levels in both SSc groups higher than those in normal controls), MIP-1alpha (P = 0.009, with levels in SSc patients with alveolitis higher than those in SSc patients without alveolitis and than those in normal controls), and RANTES (P = 0.03, with levels in SSc patients without alveolitis higher than those in normal controls). With the exception of RANTES, the highest levels were detected in SSc patients with alveolitis. CONCLUSION: Each of these cytokines, either alone or in combination, may play an important role in the pathogenesis of pulmonary fibrosis in SSc.

Adult↗
PubMed1997

Symptomatic spinal calcinosis in systemic sclerosis (scleroderma).

Two patients with diffuse cutaneous systemic sclerosis and spinal calcification, involving the lumbar spine in one and the cervical spine in the other, are described. Computed tomography-guided aspiration of the calcific masses was performed, and material aspirated from one patient was shown to be apatite, Ca5(PO4)3OH. One patient showed improvement following lumbar laminotomy, hemilaminectomy, and diskectomy.

Calcinosis↗
PubMed1997

Variable effects on murine pregnancy of immunoglobulin G fractions from women with antiphospholipid antibodies.

OBJECTIVE: Initial studies showed that passive immunization with human immunoglobulin G fractions containing antiphospholipid antibodies can result in murine fetal loss. We intended to use the murine model to study mechanisms of fetal loss associated with antiphospholipid antibodies. However, we have since found variable effects of antiphospholipid antibodies on murine pregnancy. The objective of this study was to determine the consistency of murine pregnancy loss from antiphospholipid antibody containing immunoglobulin G fraction. STUDY DESIGN: Pregnant C3H/HeN (mated with C57B1/6 males) and BALB/c (mated with BALB/c males) mice were passively immunized with antiphospholipid antibody containing human immunoglobulin G fraction from 20 women with antiphospholipid syndrome. The mice received either a single dose of 10 to 30 mg on day 12 of pregnancy or 10 mg per day on days 12 to 14 of gestation. Some mice receiving each dose of immunoglobulin G fraction were bled to confirm serum levels of anticardiolipin antibodies. Mice were killed on day 15 and the fetal status was determined. RESULTS: Overall, passive immunization with individual antiphospholipid antibody containing immunoglobulin G fractions resulted in 801 live pups (75%), 232 fetal deaths (22%), and 38 resorptions (3%) in 131 mice. The effect of immunoglobulin G fractions from individual patients was highly variable. Immunoglobulin G fraction from eight women resulted in high rates of fetal loss. However, in spite of high levels of anticardiolipin antibodies, fetal outcome was normal in mice immunized with immunoglobulin G fraction from the majority of women. The rate of fetal death did not uniformly increase with increasing doses of immunoglobulin G fraction and was unrelated to the donor's medical history. Fetal outcome was similar for both C3H/HeN and BALB/c mice. CONCLUSIONS: Human antiphospholipid antibodies have variable effects on murine pregnancy outcome. Characterization of antiphospholipid antibodies that do and do not cause murine fetal loss may provide insight into epitopes relevant to fetal loss associated with antiphospholipid syndrome.

Adult↗
PubMed1997

Bacterial lipopolysaccharide-mediated murine fetal death: the role of interleukin-1.

OBJECTIVE: Our purpose was to determine whether interleukin-1 is an important mediator of lipopolysaccharide-induced fetal death and, if so, whether interleukin-1 causes fetal death by inducing prostanoid formation in gestational tissues. STUDY DESIGN: Pregnant C3H/HeN mice were administered lipopolysaccharide, interleukin-1alpha, interleukin-beta, or vehicle on days 11 to 13 of pregnancy. Mice were killed 72 hours later and the fetal status was determined. Some mice were pretreated with anti-interleukin-1-receptor antibodies or indomethacin. Decidual explants were established from treated mice, and supernatants were assayed for interleukin-1beta and prostaglandin E2. RESULTS: Decidua taken from lipopolysaccharide-treated mice produced significantly increased amounts of interleukin-1beta, and pretreatment with anti-interleukin-1-receptor antibodies reduced the proportion of fetal deaths after lipopolysaccharide administration from 100% to 33%. The administration of interleukin-1alpha caused fetal death in a dose-dependent fashion, and decidua taken from interleukin-1-treated mice produced significantly increased amounts of prostaglandin E2. However, pretreatment with doses of indomethacin that abrogated decidual prostaglandin E2 production did not reduce the proportion of fetal death after interleukin-1alpha administration. CONCLUSIONS: Interleukin-1 is an important mediator of lipopolysaccharide-induced fetal death and causes fetal death by prostaglandin-independent effects.

Animals↗
PubMed1997

Pathogenic antibodies in women with obstetric features of antiphospholipid syndrome who have negative test results for lupus anticoagulant and anticardiolipin antibodies.

OBJECTIVE: Our goal was to determine whether women with clinical features of antiphospholipid syndrome but negative test results for lupus anticoagulant and anticardiolipin antibodies have pathogenic antibodies not identified by currently used methods. STUDY DESIGN: Sera were obtained from women with clinical features associated with antiphospholipid antibodies who had negative test results for lupus anticoagulant and anticardiolipin antibodies (antiphospholipid syndrome-like). We studied (1) the effect of passive immunization with their purified immunoglobulin G fraction on murine pregnancy (n = 35) and (2) the presence of antiphospholipid antibodies other than lupus anticoagulant or anticardiolipin antibodies (n = 39). Sera were also retested for anticardiolipin antibodies and lupus anticoagulant. RESULTS: Fetal loss occurred in 235 of 1088 (22%) pups in 137 mice immunized with immunoglobulin G fraction from antiphospholipid syndrome-like women compared with 23 of 402 (6%) pups in 53 control mice. Immunoglobulin G from 11 study patients resulted in the loss of at least one third of the exposed pups. Five women had positive levels of antiphosphatidylserine antibodies (>99th percentile). All levels were low positive, and three women also had low-positive levels of anticardiolipin antibodies on repeat testing. Five of the 11 (45%) women whose immunoglobulin G fractions caused at least 33% fetal loss also had positive test results for antiphospholipid antibodies. CONCLUSIONS: A subset of women with clinical disorders suspicious for antiphospholipid syndrome but who had negative test results for lupus anticoagulant and anticardiolipin antibodies by current methods have serum immunoglobulin G that is pathogenic to murine pregnancy. Testing for pathogenic immunoglobulin G may provide additional means to identify women with an as yet uncharacterized immune condition. The clinical relevance of low levels of antiphospholipid antibodies in these women remains unproved.

Abortion, Habitual↗
PubMed1997

Immunology update: symposium on antiphospholipid antibodies.

The seventh international symposium on antiphospholipid antibodies was held in New Orleans, LA, USA, on October 9-13, 1996. The meeting was attended by over 230 people and was hosted by Azzudin E. Gharavi and Wendell A. Wilson. Workshops were also conducted on assays for lupus anticoagulant, antiphospholipid antibodies, and anti-endothelial cell antibodies.

Allergy and Immunology↗
PubMed1997

Increased activity of the alpha 1(I) procollagen promoter in skin fibroblasts from patients with chronic eosinophilia-myalgia syndrome.

Eosinophilia-myalgia syndrome (EMS), a novel L-tryptophan-associated disease, which occurred as an epidemic in 1989, is characterized by diffuse fibrosis of the skin. The objective of these studies was to compare the in vitro expression of the gene encoding the human alpha 1(I) procollagen (COL1A1) in dermal fibroblasts derived from patients with long-standing EMS and from healthy controls. Early passage fibroblasts in culture were transiently transfected with a series of progressively 5' deleted human COL1A1 promoter-CAT reporter gene DNA constructs. Resultant CAT activity was assayed in the cytoplasmic extracts. Following transient transfection, COL1A1 promoter activity in 4/5 fibroblast cell lines derived from patients with EMS was two-to threefold greater than in matched normal fibroblasts. Deletion analysis indicated that CAT activity was highest, and displayed the greatest increase in EMS vs normal fibroblasts, with promoter constructs spanning 174 bp upstream from the COL1A1 transcription start site. The study shows increased CAT activity driven by a 174 bp fragment of COL1A1 in transiently transfected skin fibroblasts from patients with EMS even in the chronic stage of disease. These findings expand on previous observations indicating increased type I collagen gene expression in EMS fibroblasts, and suggest that fibrosis in L-tryptophan-induced EMS is associated with transcriptional activation of type I collagen gene expression, which persists even following cessation of L-tryptophan use.

Adult↗
PubMed1997

Pathological manifestations in murine Lyme disease: association with tissue invasion and spirochete persistence.

The clinical manifestations of human Lyme disease present with a spectrum of tissue or organ involvement and severity of symptoms. The murine model of Lyme disease has proved to be an accurate reflection of many of the human symptoms of disease and has been particularly useful for studying development of subacute arthritis and tendonitis. Direct tissue invasion by Borrelia burgdorferi and persistence of high levels of spirochetes in tissues are important components of arthritis development. The outer-surface lipoproteins contain a biologically active lipid-modified moiety with potent ability to stimulate inflammatory cytokine production and other inflammatory mediators such as nitric oxide. Localized inflammation stimulated by these lipoproteins may be the trigger for neutrophil infiltration, synovial proliferation, and other events associated with this arthritis. Invasion of maternal uterine tissue, but not direct invasion of fetal tissue, is associated with low levels of pregnancy loss in mice infected during gestation, consistent with the detrimental effect of inflammatory cytokines on pregnancy.

Animals↗
PubMed1997

Intravenous immune globulin in the management of severe Rh D hemolytic disease.

Although intrauterine fetal transfusion has improved dramatically perinatal outcome in Rh D alloimmunization, in some cases the fetus is affected before transfusion is possible. Immune globulin (IVIG) administration is being increasingly used to successfully treat a variety of immune-mediated diseases, such as pregnancies affected by platelet alloimmunization. Although only a limited number of pregnancies have been reported, favorable outcomes with IVIG treatment of severe Rh disease have been described. We present a case report, review the published experience with IVIG treatment in severe, early-onset anti-D sensitization, and propose that IVIG may have an adjunctive role in the treatment of severe Rh isoimmunization.

Adult↗
PubMed1997

Antiphospholipid antibodies in patients with eosinophilia myalgia and toxic oil syndrome.

OBJECTIVE: To explore whether antiphospholipid antibodies (aPL) are markers of vascular related damage or merely evidence of toxic related autoimmunity, we investigated the presence of different aPL in patients with toxic oil syndrome (TOS) and compared the profile with patients with eosinophilia myalgia syndrome (EMS). METHODS: Reactivity against cardiolipin, P-serine, P-inositol, and P-choline was investigated by ELISA in the blood of 266 patients with acute and chronic TOS, 25 healthy relatives of TOS patients, and 48 patients with EMS. RESULTS: 32% of TOS and 13% of EMS patients had IgG antibodies against cardiolipin and other polyanions. 20% of both TOS and EMS patients presented IgM antibodies against anionic and zwitterionic phospholipids. 36% of TOS healthy relatives had IgM antibodies against differently charged phospholipids. Among 200 patients with chronic TOS, there was no significant association between antibodies and clinical manifestations. CONCLUSION: aPL with different specificity are present in a high percentage of patients with TOS and EMS. The significance of these antibodies remains unclear.

Antibodies, Antiphospholipid↗