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S Ullman

Publications and source records attributed to S Ullman.

At least 19 recordsLinked to original sources
PubMed2005

Absence of high-affinity calreticulin autoantibodies in patients with systemic rheumatic diseases and coeliac disease.

Calreticulin has been reported to be an autoantigen in various autoimmune connective tissue diseases and in coeliac disease. Previous studies have used incubation buffers with low salt and low detergent concentrations (low stringency conditions) with serum albumin or other proteins as a blocking agent. Using these conditions we found a relatively high level of non-specific binding in many sera. Antibodies to proteins that are used as blocking reagents in ELISA (bovine serum albumin (BSA), ovalbumin, skimmed milk powder) are frequently present in sera, and these may cause false-positive results. Moreover, the low isoelectric point of calreticulin and its chaperone properties may give rise to false-positive results under low stringency conditions. We report that the use of a simple buffer without protein (50 mM Tris, pH 7.5, 1% Tween 20, 0.3 M NaCl) removes most of the problems with unwanted binding (high stringency conditions). Using the high stringency conditions, we screened sera from 107 patients with systemic lupus erythematosus, sera from patients with other systemic autoimmune diseases and from children with coeliac disease for the presence of high-affinity calreticulin autoantibodies by immunoblotting and ELISA. None of the sera contained high-affinity calreticulin antibodies. It is concluded that calreticulin is not a common autoantigen in patients with autoimmune connective tissue diseases or coeliac disease.

Autoantibodies↗
PubMed2001

Influence of clinical features, serum antinuclear antibodies, and lung function on survival of patients with systemic sclerosis.

OBJECTIVE: To evaluate the independent contribution of several clinical and laboratory variables to the mortality of a cohort of Danish patients with systemic sclerosis (SSc). METHODS: A cohort of 174 patients with incident SSc was retrospectively identified using clinical charts and study records of all new patients with SSc. Disease onset was defined as the time of onset of cutaneous sclerosis. Vital status and causes of death were determined at the end of the observation period. Data on clinical status and pulmonary function were obtained. Antitopoisomerase I (anti-topo I), anticentromere, anti-U1-RNP, anti-U3-RNP, anti-Th-RNP, and anti-RNA polymerase (anti-RNAP) antibodies were determined by means of double immunodiffusion, immunofluorescence, hemagglutination technique, radioactively labelled antisense riboprobes, and ELISA, respectively. RESULTS: Patients were followed for a mean period of 13.3 yrs; 16 died of an SSc related condition and 50 of other causes. Pulmonary fibrosis, DLCO reduction < 40% of the expected, diffuse cutaneous involvement, SSc nephropathy, cardiac disease, and anti-topo I and anti-RNAP antibody were related to decreased survival due to SSc. Variables that entered a Cox regression model of SSc related mortality were right heart failure (RR 12.4, 95% CI 2.5-60), diffuse SSc (RR 7.8, 95% CI 1.8-35), SSc nephropathy (RR 6.1, 95% CI 1.8-21), and DLCO < 40% (RR 4.8, 95% CI 1.1-20). The relative risk of developing right heart failure and diffuse SSc given the presence of anti-RNAP antibody was 14 (p = 0.0001) and 1.9 (p = 0.01), respectively. The corresponding figures for anti-topo I antibody were 4.6 (p = 0.02) and 2.0 (p = 0.01). CONCLUSION: SSc related mortality was associated with right heart failure and diffuse SSc, both of which were also associated with the presence of anti-topo I and anti-RNAP antibody. The prognostic value of these autoantibodies may lie in the early course of the disease when specific morbidity has not yet evolved.

Adolescent↗
PubMed2001

Viscoelastic properties and flexibility of the human muscle-tendon unit in benign joint hypermobility syndrome.

OBJECTIVE: To examine the passive energy absorption of the hamstring muscle-tendon unit in 9 women with benign joint hypermobility syndrome (BJHS) and 9 age and sex matched controls. METHODS: Resistance to stretch was measured as knee flexion moment (N.m) with an isokinetic dynamometer during passive knee extension. The angle that induced a stretch sensation without pain was the maximal stretch angle. Force, angle, angular velocity (0.09 rad/s), and electromyograph were simultaneously and continuously recorded during the stretch. Hamstring cross sectional area was obtained with magnetic resonance imaging. RESULTS: Forearm skin extensibility was greater for BJHS (3.6+/-0.5 cm) than for controls (1.3+/-0.2 cm) (p < 0.01). Similarly, the Beighton score was greater for BJHS (6.6+/-0.8) than for controls (0.4+/-0.2) (p < 0.001). Maximal stretch angle was greater for BJHS (delta1.35+/-0.07 rad) compared to controls (delta0.98+/-0.05 rad) (p < 0.001), and the corresponding peak moment was also greater for BJHS (1.3+/-0.4 Nm/cm2) than for controls (0.6+/-0.1 Nm/cm2) (p < 0.01). For a given mutual angle the passive energy absorption was the same for both groups, but at the maximal stretch angle the total area-normalized energy was greater for BJHS (0.36+/-0.04 J/cm2) than for controls (0.18+/-0.28 J/cm2) (p < 0.001). CONCLUSION: The lack of difference in passive energy absorption for a given mutual stretch angle suggests that passive properties of the muscle-tendon unit of BJHS are similar to those of controls. However, the greater maximal stretch angle and corresponding peak moment in BJHS suggests a greater subjective tolerance to passive stretch. That is, increased flexibility in BJHS is not a function of altered passive properties of the muscle-tendon complex. It remains unknown if the enhanced tolerance to passive tension plays a role in the development of musculoskeletal ailment.

Adult↗
PubMed2000

Determination of autoantibodies to annexin XI in systemic autoimmune diseases.

Annexin XI, a calcyclin-associated protein, has been shown to be identical to a 56,000 Da antigen recognized by antibodies found in sera from patients suffering from systemic autoimmune diseases. In this work hexahistidine-tagged recombinant annexin XI (His6- rAnn XI) was used as antigen in ELISA experiments for determination of autoantibodies to annexin XI in sera of patients with systemic rheumatic autoimmune diseases. Immunoblotting with HeLa cell extract and with His6-rAnn XI as antigen was used for confirmation of positive ELISA results. We found eleven anti-annexin XI positive sera (3.9%) out of 282 sera from patients with systemic rheumatic diseases. The highest number of annexin XI positive sera were found in primary antiphospholipid syndrome (3/17), and in subacute lupus erythematosus (1/6), while lower frequencies of positive sera were found in patients with systemic sclerosis (5/137), rheumatoid arthritis (1/21), and systemic lupus erythematosus (1/58). Sera from healthy donors and patients with chronic infections were negative, except for one Salmonella typhimurium antibody positive serum. Autoantibodies to annexin XI were found to relate to thrombosis, but not to other clinical or laboratory features. A relation between antibodies to annexins and thrombosis has so far only been known for annexin V.

Adult↗
PubMed1999

[Scleroderma--systemic sclerosis. Serology, lung function and survival].

Patients with systemic sclerosis (SSc) were studied with regard to the presence of antinuclear antibodies (ANA) and their clinical correlates (n = 230), pulmonary function (n = 176), and mortality and causes of death (n = 344). ANA were found in 85%. Anti-centromere antibodies were found in 34%, anti-Scl-70 antibodies in 13% and anti-U1-RNP antibodies in 6.5%. These serological groups were associated with limited SSc, diffuse SSc, and myositis/arthritis, respectively. The most prevalent finding at first lung function test was isolated reduction of diffusion capacity (47%). Further deterioration of diffusion capacity was related to the presence of anti-centromere antibodies and increased sedimentation rate. The standardized mortality rate (SMR) was 2.9, higher in young patients (SMR = 13) and patients with diffuse SSc (SMR = 4.5).

Adolescent↗
PubMed1999

Computation of pattern invariance in brain-like structures.

A fundamental capacity of the perceptual systems and the brain in general is to deal with the novel and the unexpected. In vision, we can effortlessly recognize a familiar object under novel viewing conditions, or recognize a new object as a member of a familiar class, such as a house, a face, or a car. This ability to generalize and deal efficiently with novel stimuli has long been considered a challenging example of brain-like computation that proved extremely difficult to replicate in artificial systems. In this paper we present an approach to generalization and invariant recognition. We focus our discussion on the problem of invariance to position in the visual field, but also sketch how similar principles could apply to other domains.The approach is based on the use of a large repertoire of partial generalizations that are built upon past experience. In the case of shift invariance, visual patterns are described as the conjunction of multiple overlapping image fragments. The invariance to the more primitive fragments is built into the system by past experience. Shift invariance of complex shapes is obtained from the invariance of their constituent fragments. We study by simulations aspects of this shift invariance method and then consider its extensions to invariant perception and classification by brain-like structures.

Journal Article↗
PubMed1999

Mortality and causes of death of 513 Danish patients with systemic lupus erythematosus.

A multicentre cohort of 513 clinic attenders with systemic lupus erythematosus (SLE) was retrospectively identified, representing 4185 patient-years of follow-up. Expected numbers of death were calculated by means of age- and sex-specific mortality rates of the general Danish population. The observed number of deaths was 122. The survival rates were 97%, 91%, 76%, 64% and 53% after 1, 5, 10, 15, and 20 years respectively. The overall mortality rate was 2.9% per year (95% CI 2.4-3.5), and the standardized mortality rate (SMR) was 4.6 (95% CI 3.8-5.5). The causes of death included active SLE (n = 19), end stage organ failure due to SLE (n = 16), infections (n = 25), malignancy (n = 9), cardiovascular disease (n = 32), and other causes (n = 21). SLE was directly related to one third of the excess mortality. In conclusion, SLE patients in the present cohort had a 4.6-fold increased mortality compared with the general population and half of the deaths were caused by SLE manifestations or infections, especially in young patients during the early period of the disease.

Adolescent↗
PubMed1999

Prognostic value of renal biopsy and clinical variables in patients with lupus nephritis and normal serum creatinine.

OBJECTIVE: To evaluate factors with possible influence on the renal outcome in patients with lupus nephritis but without chronic renal insufficiency (CRI). METHODS: Renal biopsies from 94 patients were re-assessed with regard to WHO class, activity, chronicity and tubulointerstitial indices without knowledge of clinical features. The outcome parameters were CRI defined as irreversibly increased serum creatinine and renal end stage disease. RESULTS: The risk ratios (RR) of developing CRI were 2.6 for active urinary sediment, 3.1 for hyaline thrombi and 7.3 for glomerular leukocyte exudation. The RR of renal end stage disease was 5.0 when the duration of renal disease exceeded one year at the time of biopsy and 4.3 when biopsy disclosed a class IV lesion. Glomerular sclerosis was also associated to renal end stage disease. CONCLUSION: Early renal biopsy and the abovementioned signs of active renal disease carry prognostic information that may have significant therapeutic implications.

Adolescent↗
PubMed1999

Twisted collagen fibrils in acrocyanosis.

Essential acrocyanosis (EA) present as a dusky discoloration of the hands as the sole symptom without any other abnormal results from laboratory investigation. Previously, the authors have found twisted collagen fibrils (TCF) in the normal skin of an EA patient. This study was intended to evaluate the significance of TCF in EA. Thirteen patients showing dusky discoloration were randomly selected and studied for TCF in normal skin by routine electron microscopy. TCF were found in 10 of 13 patients; 3 patients with only the discoloration (EA), 3 with the mild symptoms which were supposed to be Ehlers-Danlos syndrome (EDS), 1 with definite symptoms of EDS, 1 with Raynaud's disease and 2 with hyperglobulinemia. TCF were the ultrastructural sign for inherited malformation of collagen fibrils. EA was probably elucidated as a vascular disorder in TCF-carrying people. EA could be included in the disease category of EDS but it seems unreasonable to force EA patients into one of the subtypes of EDS. For pathogenesis, the inherited dysfunction in the hypertrophic pericytes of the subpapillary vascular plexus was presumed.

Adult↗
PubMed1998

A multicentre study of 513 Danish patients with systemic lupus erythematosus. I. Disease manifestations and analyses of clinical subsets.

A Danish multicentre study was undertaken of the manifestations, infections, thrombotic events, survival and predictive factors of survival in 513 Danish patients with systemic lupus erythematosus (SLE) according to the 1982 classification criteria of the American College of Rheumatology. The mean duration of follow-up was 8.2 years from diagnosis and 12.8 years from first symptom. This paper describes the most common clinical and laboratory manifestations and their relationship to sex and age at the time of onset and diagnosis. Cluster analysis revealed three clinically defined clusters at the time of disease onset. Cluster 1 (57% of patients) consisted of relatively elderly patients without nephropathy or malar rash, but with a high prevalence of discoid lesions. Cluster 2 (18%) consisted of patients with nephropathy, a third of whom also developed serositis and lymphopenia. The patients of the third cluster (25%) all had malar rash and half were photosensitive. Follow-up showed that the patients of cluster 2 developed azotaemia, large proteinuria, arterial hypertension and myositis significantly more often than did the rest of the patients, but the mortality was not increased. The risk of developing renal end-stage disease was highest in men with early-onset disease.

Adolescent↗
PubMed1998

A multicentre study of 513 Danish patients with systemic lupus erythematosus. II. Disease mortality and clinical factors of prognostic value.

In this Danish multicentre study, predictive clinical factors of mortality and survival were calculated for 513 patients with systemic lupus erythematosus (SLE), 122 of whom died within a mean observation period of 8.2 years equalling a mortality rate of 2.9% per year. Survival rates were 97%, 91%, 76% and 64% after 1, 5, 10 and 15 years, respectively. The direct causes of death included SLE (n = 35), infections (n = 25), malignancy (n = 9), cardiovascular disease (n = 32) and other causes (n = 21). Uni- and multivariate analyses of survival and mortality were performed for all deaths and for SLE-related deaths. Azotaemia (one-fifth of the patients) was a strong predictor of increased overall and SLE-related mortality, but nephropathy per se (one-half of the patients) and large proteinuria (one-sixth of the patients) were unrelated to survival. Haemolytic anaemia had a significant negative influence on survival related to mortality caused by infections. Diffuse central nervous system disease and myocarditis were related to increased SLE-related mortality, whereas photosensitivity predicted a decreased mortality. Non-fatal infections and thrombotic events predicted a decreased overall survival. Since 1980 the mortality caused by SLE manifestations has decreased significantly.

Adolescent↗
PubMed1998

Three-dimensional object recognition based on the combination of views.

Visual object recognition is complicated by the fact that the same 3D object can give rise to a large variety of projected images that depend on the viewing conditions, such as viewing direction, distance, and illumination. This paper describes a computational approach that uses combinations of a small number of object views to deal with the effects of viewing direction. The first part of the paper is an overview of the approach based on previous work. It is then shown that, in agreement with psychophysical evidence, the view-combination approach can use views of different class members rather than multiple views of a single object, to obtain class-based generalization. A number of extensions to the basic scheme are considered, including the use of non-linear combinations, using 3D versus 2D information, and the role of coarse classification on the way to precise identification. Finally, psychophysical and biological aspects of the view-combination approach are discussed. Compared with approaches that treat object recognition as a symbolic high-level activity, in the view-combination approach the emphasis is on processes that are simpler and pictorial in nature.

Depth Perception↗
PubMed1998

Clinical features and serum antinuclear antibodies in 230 Danish patients with systemic sclerosis.

The objective was to investigate the relationship between the presence of different types of antinuclear antibodies (ANA) in patients with systemic sclerosis (SSc) and the presence of clinical features. Sera from 230 patients with SSc were tested for the presence of ANA, including anticentromere antibodies (ab), antitopoisomerase I ab, anti-U1 RNP ab and antinucleolar ab, including anti-Th RNP, anti-U3 RNP and anti-U17 RNP. Clinical features were registered prospectively in a clinical database. Eighty-two per cent of the patients were women. The median age was 58 yr (45-67, quartiles) and median age at disease onset was 44 (30-55) yr. ANA were found in 86% of the patients (anticentromere: 34%; antitopoisomerase I: 14%; anti-U1 RNP: 6.5%; antinucleolar total: 16%; anti-Th RNP: 2.2%; anti-U3 RNP: 3.5%; anti-U17 RNP: 0%). Anticentromere ab were found to be related to a high prevalence of calcinosis, telangiectasia, digital ulcers, acrosclerosis, primary biliary cirrhosis, isolated reduction of pulmonary diffusing capacity, and a low prevalence of radiological evidence of pulmonary fibrosis. Antitopoisomerase I ab were associated with a high prevalence of digital joint deformity, distal osteolysis, radiological signs of pulmonary fibrosis, a low prevalence of calcinosis and late onset of disease. Anti-U1 RNP ab were related to a high prevalence of arthritis and myositis, a low prevalence of calcinosis, and early disease onset. The presence of antinucleolar ab, including anti-U3 RNP and anti-Th RNP, was not significantly related to any particular clinical features in this study; possibly due to the small number of patients with these ab. The presence of anticentromere, antitopoisomerase I and anti-U1 RNP ab in the serum was also found to have previously described clinical correlations in a group of Danish SSc patients.

Adolescent↗
PubMed1998

Mortality and causes of death of 344 Danish patients with systemic sclerosis (scleroderma)

OBJECTIVE: To determine survival, mortality and causes of death in Danish patients with systemic sclerosis (scleroderma), and to analyse how these parameters are influenced by demographic variables and the extent of skin involvement. METHODS: A cohort of 344 patients with incident systemic sclerosis (SSc) after 1 January 1960 was retrospectively identified, representing 3716 patient-years of follow-up. The vital status at the end of the study ultimo 1996 was established by reviewing the clinical charts and by contacting the Danish Central Person Register. The causes of death were based on information obtained from the hospital charts and the autopsy reports (80%) and death certificates (20%). The extent of skin sclerosis was described by means of a two-subset model (limited and diffuse involvement) and a three-subset model (digital, extremity and truncal involvement) in all patients. Expected numbers of deaths were calculated by means of age- and sex-specific mortality rates of the general Danish population. RESULTS: Crude mortality rates were 6.5 and 3.9%/yr, respectively, in men and women. The standardized mortality ratio (SMR) was 2.9 (95% CI 2.5-3.4) and was not significantly influenced by sex or age at disease onset. Mortality rates were significantly increased in patients with diffuse skin sclerosis (SMR 4.5, 95% CI 3.5-5.7) and patients under the age of 35 yr (SMR 13, 95% CI 2.7-37). Of the 160 patients who died during the study, 41 deaths (26%) were SSc related, accounting for one-third of the excess mortality. CONCLUSION: We found a significantly increased mortality in patients with SSc, particularly in the subset of patients with diffuse skin sclerosis and in young patients. The excess mortality was due to an increase in both the SSc-related mortality and the unrelated mortality. However, all other subsets also had a significantly increased risk of death, mainly due to an increased risk of death due to causes unrelated to SSc, cancer among others. The fact that the unrelated mortality in SSc was found to be 2-fold increased suggests that the excess mortality that was classified as unrelated should more appropriately be termed indirectly SSc related.

Adolescent↗
PubMed1998

Oral iloprost in Raynaud's phenomenon secondary to systemic sclerosis: a multicentre, placebo-controlled, dose-comparison study.

OBJECTIVE: To identify the optimal dose of oral iloprost on the basis of efficacy and tolerability in patients with Raynaud's phenomenon secondary to systemic sclerosis. DESIGN: Multicentre, randomized, parallel-group comparison of two different doses of oral iloprost and placebo. SETTING: European university hospitals. PATIENTS: A total of 103 patients with Raynaud's phenomenon secondary to systemic sclerosis. INTERVENTION: Patients received one of three treatments for 6 weeks: placebo, oral iloprost 50 microg or oral iloprost 100 microg. Each treatment was taken twice daily, giving total daily doses of iloprost of 100 and 200 microg. MEASUREMENTS: The frequency, total daily duration and severity of Raynaud's attacks were recorded in a specially designed patient diary; physician's global assessment and adverse events were recorded at visits to the clinic. Analysis was performed on an intention-to-treat population. RESULTS: A total of 103 patients were recruited, 89 completed the assessments throughout the treatment period and 82 completed an additional 6 weeks of follow-up after treatment. Thirty-five patients received placebo, 33 received iloprost 50 microg and 35 received iloprost 100 microg. The mean percentage reductions in the frequency, total daily duration and severity of Raynaud's attacks were numerically greater in the iloprost groups at the end of treatment and at the end of follow-up. At the end of treatment (6 weeks), there were significant treatment differences in the total daily duration of attacks (P = 0.03), but not in the severity (P = 0.07) or the frequency of attacks (P = 0.37). At the end of follow-up (12 weeks), there were significant treatment differences in the total daily duration of attacks (P = 0.001) and in the severity of attacks (P = 0.007), but not in the frequency of attacks (P = 0.07). Percentages of patients improved at the end of treatment as assessed by the physician were 44% placebo, 57% iloprost 50 microg and 64% iloprost 100 microg (not significant). Side-effects were reported by 80% of patients on placebo, 85% on oral iloprost 50 microg and 97% on oral iloprost 100 microg. Premature discontinuations of treatment in each group were 9, 30 and 51%, respectively, with 6, 27 and 51% being due to adverse events. CONCLUSION: The results on the daily duration of Raynaud's attacks suggest that both 50 and 100 microg oral iloprost twice daily may be effective in the treatment of Raynaud's phenomenon secondary to systemic sclerosis. The 50 microg iloprost dose was better tolerated in this patient group.

Administration, Oral↗
PubMed1998

Elastic fibers in dermis of juvenile elastoma.

To explore the ultrastructure of elastic fibers in juvenile elastoma, three patients (two without osteopoikilosis and one under examination of bones and joints) were studied by routine electron microscopy. In addition to normal elastic fibers, all the patients also exhibited alterations in elastic fibers. The altered ultrastructures showed lucent, homogenous matrix without peripheral microfibrils. The homogenous matrix were seen in various extensions from the small protrusions of the normal elastic fibers to the complete replacement of the entire fibers. Collagen fibrils occasionally showed twisted figures. Normal shapes of dermal glycosaminoglycans were increased in number. It seems likely that the lucent, homogenous matrix without peripheral microfibrils are the characteristic changes of elastic fibers in juvenile elastoma. The alteration could be nevoid in nature.

Actin Cytoskeleton↗
PubMed1997

A longitudinal study of pulmonary function in Danish patients with systemic sclerosis.

OBJECTIVE: To determine the types, prevalence and development of respiratory abnormalities in patients with systemic sclerosis (SSc), and to correlate the results with clinical and serological findings. METHODS: 176 patients with SSc observed longitudinally were retrospectively included in the study. The change per year of vital capacity (VC), forced expiratory volume in one second/vital capacity (FEV1/VC), diffusing capacity (DLco) and diffusing constant (Kco) of carbon monoxide from the first till the latest pulmonary function test were correlated to clinical and serological findings, including anti-centromere, anti-Scl-70, and antinucleolar antibodies. RESULTS: An isolated reduction of DLco was seen in 47% and a restrictive ventilatory pattern in 25% of the patients. Restrictive ventilatory pattern correlated to pulmonary fibrosis, dyspnoea, a low prevalence (13%) of anti-centromere antibodies and a high prevalence of anti-Scl-70 antibodies (36%). Progression of DLco reduction was related to long disease duration, presence of anti-centromere antibodies and absence of treatment with penicillamine. CONCLUSION: Pulmonary involvement is common in patients with SSc. The occurrence of different serological abnormalities in patients with restrictive disease and in patients with progressive isolated reduction of DLco, suggests that the two types of pulmonary damage may have different pathogeneses rather than being different stages in the progression of pulmonary damage.

Adult↗