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Biomedical subjects

G Sturfelt

Publications and source records attributed to G Sturfelt.

At least 127 records · Page 7Linked to original sources
PubMed1985

Sequential studies of complement activation in systemic lupus erythematosus.

C1 and C3 activation, measured as C1r-C1s-C1 inactivator C1s-C1r-C1IA complexes in serum and circulating C3d were studied in serial samples from 33 patients with SLE. All patients demonstrated exacerbations during observation periods of 10-30 months and were divided into groups according to principal clincal features (mild SLE, severe extra-renal SLE, and lupus glomerulonephritis). Increased C1 activation was consistently found during exacerbation. C3d in plasma was a feature associated with severe disease flares. Activation of C1, but not of C3, was documented before flare-ups of disease activity, but such predictive information was mostly restricted to patients with extra-renal disease. C2 cleavage in plasma, studied serially in a few patients, appeared to be closely associated with C1 activation. Circulating immune complexes, measured with solid-phase C1q assay, did not always increase before development of clinical manifestations. Remission of symptoms was paralleled by decreasing concentrations of C1r-C1s-C1IA and of, when present, C3d. Similar findings were made for immune complexes but only in severe disease. Persisting C3d was observed in 3 patients, who subsequently developed renal failure. C1q levels were transiently low during flare-ups of lupus glomerulonephritis, but otherwise the concentrations of C1q, C4 and C3 did not show consistent patterns of variation in relation to disease activity.

Adolescent↗
PubMed1985

Systemic lupus erythematosus and infection: a controlled and prospective study including an epidemiological group.

An epidemiological group of 60 SLE patients was studied; 162 infections were observed prospectively for an aggregate of 1366 months. Bacterial infection was more frequent in the SLE patients than in matched controls but only slightly more frequent than in matched rheumatoid arthritis patients. The rheumatoid arthritis patients, also matched with regard to corticosteroid dosage, showed a tendency towards an increased infection rate only. Lower urinary tract infections were comparable in all three matched groups. In a total of 102 SLE patients studied, including the epidemiological group, clinical SLE activity was accompanied by an increase in the frequency of bacterial infection. In 49 patients bacterial infections were more common after flare than before. There was a high incidence of mucocutaneous infections induced by S. aureus, where skin traumatisation was an added risk factor. No increase of opportunistic infections was found in matched groups, but 26 such infections occurred in the subjects as a whole, and they were seen to be more frequent in conjunction with steroid-treated active SLE. Admission to hospital because of suspected infection was common, and infection was the cause or a contributory factor in five of the seven deaths among SLE patients.

Adrenal Cortex Hormones↗
PubMed1984

Serum level of complement factor D in systemic lupus erythematosus--an indicator of glomerular filtration rate.

Serum levels of complement factor D, a low molecular weight (LMW) protein, were high and inversely correlated with glomerular filtration rate (GFR) determined in 19 patients with lupus glomerulonephritis (LGN). Factor D was significantly closer correlated with S-creatinine than were two other LMW proteins, beta 2-microglobulin and gamma-trace in 22 LGN patients. Close correlations between each of the LMW proteins and S-creatinine were found in patients with a non-inflammatory disorder, polycystic kidney disease. Slightly increased beta 2-microglobulin concentrations were found in 15 of 20 systemic lupus erythematosus (SLE) patients without renal involvement, while factor D and gamma-trace showed normal values in most of these patients. The findings imply that serum concentrations of complement factor D in SLE are mainly determined by the GFR.

Adolescent↗
PubMed1984

Cleavage of C2 in pathological serum and plasma studied by crossed immunoelectrophoresis.

A cleavage product of C2, C2a was demonstrated by crossed immunoelectrophoresis in serum and EDTA plasma from patients with active systemic lupus erythematosus (SLE), patients in the early phase of acute poststreptococcal glomerulonephritis (AGN), and from two males with congenital deficiency of C1(-) inactivator, one of whom had symptoms of hereditary angioedema. C2a was not found in normal serum and plasma. C2 was more stable in plasma than in serum with regard to the effects of storage in room temperature and of repeated freezing and thawing. C2a concentrations were higher in serum than in plasma samples from SLE and AGN patients. Expressed in per cent of the total C2 protein, C2a was inversely correlated (r = -0.91) with the C2 hemolytic activity in the samples, which explains discrepancies between the results of immunochemical and functional assays, when used to measure C2 concentrations in disease.

Adult↗
PubMed1984

Complement components, complement activation, and acute phase response in systemic lupus erythematosus.

The investigation concerned 33 systemic lupus erythematosus (SLE) patients assigned to three groups representing mild SLE, more severe extra renal SLE, and SLE with significant renal involvement. In patients with extrarenal disease, the inflammatory plasma protein response was often pronounced during exacerbation, as evidenced by markedly increased concentrations of C-reactive protein (CRP), alpha 1-antichymotrypsin, alpha 1-antitrypsin, and orosomucoid. CRP responses were rare in patients with renal involvement, despite the increased concentrations of other acute-phase reactants in some of these patients. Superimposed bacterial infections were not clearly distinguished by raised CRP concentrations. The classical pathway of complement was activated in all patients during exacerbation, as indicated by increased concentrations of C1r-C1s-C1 inactivator complexes and C2a fragments. C1, C2, and probably also C3 activation varied according to the amounts of circulating C1q-binding immune complexes, as measured by solid-phase assay. Manifest hypocomplementemia was usually associated with glomerulonephritis. Participation of complement components in the inflammatory plasma protein response apparently counteracted the development of hypocomplementemia in many patients with extrarenal SLE. Circulating C3d was detected in all patients during exacerbation of renal disease and in most patients with severe extrarenal manifestations. Inverse relationships were found between immunochemical C2 concentrations and the percentage of cleaved C2 and between C3 and C3d. There was no appreciable consumption of factors B and D and properdin of the alternative pathway in the patients. High concentrations of factor D, a low molecular weight protein, were exclusively found in patients with renal involvement and could be ascribed to retention due to reduced glomerular filtration.

Antigen-Antibody Complex↗
PubMed1983

Human factor D of the alternative pathway: purification and quantitation by enzyme amplified electroimmunoassay.

Purified factor D was prepared with a yield of about 30%. Monospecific antiserum was raised in rabbits. Immunochemical quantitation of factor D in serum and plasma was performed by electroimmunoassay and a sensitive staining technique based on enzyme amplification. Peroxidase-labeled swine antibodies to rabbit immunoglobulin were applied to the gel after electrophoresis. Immune precipitates were then visualized by staining for peroxidase activity. Factor D could be detected at 50 micrograms/l. The normal concentration of D in serum was 1.6 mg/l, as assessed by this assay.

Animals↗
PubMed1983

Complement components, C1 activation and disease activity in SLE.

Laboratory parameters were studied in 8 systemic lupus erythematosus patients during periods of high and low disease activity, mainly as defined by clinical criteria. Renal manifestations were present in 6 patients 5 of which showed antibodies to native DNA. C-reactive protein was raised in 3 patients. Only 1 of these showed a superimposed bacterial infection. Markedly high concentrations of C1r-C1s-C1 inactivator cOmplexes (C1r-C1s-Cl IA) in the sera provided direct evidence of C1 activation independent of disease activity. During active disease. C1r-C1s-C1 IA were correlated with C1q binding immune complexes as measured by solid phase, but not by fluid phase assay. Immunochemical concentrations of C1q, C4 and C3 and functional C2 were decreased in active SLE, consistent with sequential activation of the classical pathway. Discrepancies were noted between functional and immunochemical assay for C2 but not for factor B. Although essentially within the normal range, the levels of C1s, C4 binding protein, C5 and properdin were lower during active than during inactive disease. The concentrations of the factors B, I and H did not suggest involvement of the alternative pathway. 1 exceptional patient showed low factor B, a relative decrease of factor I and the presence of Bb fragments in plasma during active SLE. Markedly high factor D values were found. This could partly be explained by reduced renal function.

Adolescent↗
PubMed1983

Nerve palsy after knee arthroplasty in patients with rheumatoid arthritis.

Forty-two consecutive knee arthroplasties on rheumatoid knees (19 Attenborough, 20 Total Condylar, 3 Marmor) were examined pre- and postoperatively for signs of below-the-knee nerve lesions. Sixteen of these knees were also studied neurophysiologically (EMG). Four patients (knees) had peroneal nerve palsy, three early and one late. Three further knees had only EMG signs of nerve lesion. Predisposing factor was correction of flexion contracture of more than 10 degrees and especially when combined with varus change in alignment. Preoperative EMG could not predict nerve lesion.

Action Potentials↗
PubMed1983

Autonomic nerve function in rheumatoid arthritis of varying severity.

Autonomic nerve function was evaluated by deep breathing and tilt table tests in 17 patients with rheumatoid arthritis (RA) and in 24 healthy control subjects. The results showed that all RA patients had increased heart rates at rest, irrespective of the severity of the disease. Patients with severe RA had increased systolic and diastolic blood pressures before and after tilting. Pronounced abnormalities in the immediate heart rate reaction to tilting indicating autonomic neuropathy (AN) were also demonstrated in patients with severe RA. The abnormal immediate reaction to tilting was mainly the result of vagal neuropathy. From the present study it is evident that severe RA may be accompanied by AN and the consequences need to be elucidated.

Adult↗
PubMed1983

Complement factor D concentrations in normal sera: comparison of immunochemical and functional determinations.

The concentration of factor D (D) was determined in the sera of 144 healthy adults and 29 healthy children by enzyme amplified electroimmunoassay (EAE), and by a hemolysis in gel (HIG) assay for D. The 95% geometric confidence areas for D in adults were 75-143% as determined by EAE, and 65-171% by the functional assay. The concentrations were given in per cent of a reference serum pool containing 1.6 mg/l of D as measured by EAE. The correlation coefficient between D values obtained by the two methods was r = 0.52 (p less than 0.001). D levels were lower in children than in adults. In the EAE purified D, and pathological sera with very high D Concentrations, gave lower precipitation peaks with dilutions performed in buffer than with dilutions in D depleted serum or human serum albumin.

Adult↗
PubMed1983

Impaired monocyte motility in sera from patients with systemic lupus erythematosus.

The influence of serum on the motility of normal monocytes in mononuclear cell preparations was investigated using a modified Boyden assay. Undiluted sera from 9 patients with active SLE and from 6 healthy controls were studied, using pooled normal serum as a reference. When the cells were suspended in SLE serum, both spontaneous motility, and motility in response to zymosan treated reference serum, were reduced. By contrast, the capacity of the SLE sera to generate chemotactic activity on zymosan treatment was hardly affected at all. In zymosan treated control sera, pronounced spreading and decreased motility of monocytes were observed, while zymosan treatment of SLE serum promoted spreading and increased the motility of cells. No consistent relationship was found between complement components and C1q binding immune complexes and the decreased monocyte motility in the SLE sera tested. Cell motility in the assay remained unaffected by the addition of prednisolone to the reference serum.

Adolescent↗
PubMed1981

Varying distribution of acetylation phenotypes in RA patients with and without Sjögren's syndrome.

The acetylator phenotype status was studied in 61 patients with rheumatoid arthritis (RA), of whom 27 had associated Sjögren's syndrome (SS). The acetylation tests were carried out by means of isoniazid and in 24 patients also with the use of dapsone; there was complete agreement between the outcome of the two tests. The results showed that the frequency of slow acetylators in the whole material was 59%. In RA patients with SS, however, the frequency of slow acetylators was as great as 78%, while it was only 44% among patients without SS (p less than 0.02). Thus, there appears to exist a (pharmaco) genetic difference between RA patients with and without SS. In addition, toxicodermias were found to be more frequent in RA patients with than without SS (P less than 0.01). However, this could not be systematically correlated to slow acetylation.

Acetylation↗
PubMed1981

Hand symptoms associated with diabetes mellitus. An investigation of 765 patients based on a questionnaire.

A number of 738 patients with diabetes mellitus (DM) and 371 matched controls answered a questionnaire constructed to detect rheumatic hand symptoms. The SM patients showed significantly more palmar thickening, indicating Dupuytren's contracture and flexor tenosynovitis, and a significantly lower frequency of neurological sensations. There was no statistically significant difference in the estimated frequency of rheumatoid arthritis between the total population and our DM population.

Diabetes Complications↗
PubMed1980

Monocyte in vitro function in systemic lupus erythematosus (SLE). II. Glass adherence and spreading in presence of SLE-sera.

Studies on glass adherence and spreading of normal blood monocytes in presence of sera from patients with systemic lupus erythematosus (SLE) were performed. Spreading was estimated by measuring the cell diameters with a microscale in a phase contrast microscope. Glass adherence (number of glass adherent cells per cultivation chamber) and spreading were found to be significantly reduced in presence of SLE-sera. Furthermore, in presence of these SLE-sera the monocytes formed clusters, which resolved after addition of normal sera. It is suggested that these observations may reflect a disturbance of monocyte membrane function possibly induced by immune complexes or through depletion of complement components in sera from patients with active SLE.

Adult↗