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Biomedical subjects

M F Kahn

Publications and source records attributed to M F Kahn.

At least 91 records · Page 5Linked to original sources
PubMed1995

Anti-vascular endothelial cell antibodies (AECA): comparison of two assay methods and clinical applications.

Vascular endothelial cells may be a target for autoantibodies (AECAs) against membrane antigens that are constitutively expressed, induced or bound to their surface. To test this hypothesis, we used an enzyme-linked immunosorbent assay (ELISA) with two types of human endothelial cells as the substrate, i.e., human umbilical cord vein endothelial cells (HUVECs) or the hybrid cell line EAhy-926 obtained by fusion of HUVECs with the bronchial carcinoma cell line A549. A comparative functional study of these two cell types demonstrated that EAhy-926 cells produced only small amounts of VIII von Willebrand factor and tissular factor, did not contain Weibel Palade bodies visible under the electron microscope, and expressed ICAM-1 and selectin E in levels of no more than 15% of those expressed by human umbilical cord vein endothelial cells both after stimulation by bacterial lipopolysaccharide and under basal conditions. However, the two assay methods yielded similar IgG AECA titers when used on sera from patients with rheumatoid vasculitis or antiphospholipid syndrome. These antibodies did not exhibit cytotoxicity for cord vein or EAhy-926 cells. They were not specific for endothelium, since their activity decreased by a mean of 40% after incubation of sera with the epithelial cell line A549. A cross-sectional study of 565 sera demonstrated that anti-vascular IgG and IgM AECAs reactive with EAhy-926 cells occurred mainly in patients with dermatomyositis (IgG, 58%; IgM, 22%), systemic scleroderma (IgG, 48%; IgM, 18%), primary Sjögren's syndrome (IgG, 44%; IgM, 12%) and secondary and primary systemic vasculitides (IgG, 38%; IgM, 18%) including Wegener's granulomatosis. A longitudinal study in patients with Wegener's granulomatosis showed that AECAS were predictive of disease activity.

Antibodies↗
PubMed1994

[Are systemic diseases of infectious origin?].

Defined as diffuse inflammatory disorders, theoretically of unknown origin, systemic diseases would thus not be of infectious origin. Nevertheless, a series of examples shows that it is possible for some, and probable for others, that a parasitic, bacterial or especially viral infection would be a triggering or maintaining factor. In addition, better means of investigation have already and will certainly lead to more precise study of this interaction. New pathophysiological mechanisms are predicted and sometimes already shown. The results have already influenced therapy. It can therefore be concluded that at least some diseases considered to by systemic are probably of infectious origin.

Arthritis↗
PubMed1994

Is diffuse sclerosing osteomyelitis of the mandible part of the synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome? Analysis of seven cases.

Diffuse sclerosing osteomyelitis of the mandible has been described as a localized disease of unknown origin. We offer evidence that mandibular involvement in the recently described synovitis acne pustulosis hyperostosis osteitis syndrome exactly fits the accepted description for diffuse sclerosing osteomyelitis of the mandible. The clinical, radiologic, and pathologic findings in seven such cases are presented and discussed.

Acne Vulgaris↗
PubMed1994

The SAPHO syndrome.

The occurrence of musculoskeletal manifestations (including synovitis, chest wall arthro-osteitis and multifocal aseptic osteomyelitis) in association with severe acne, palmoplantar pustulosis and perhaps with some presentations of psoriasis, have been described by many authors in the past 30 years. These different multifaceted descriptions have been designated by a variety of terms. More recently, a possible link between these conditions and spondarthritides has also been underlined by a slightly increased prevalence of HLA-B27 and occasional occurrences of sacroiliitis, chronic inflammatory bowel disease and possibly psoriasis. An acronym, the SAPHO syndrome (which stands for Synovitis, Acne, Pustulosis, Hyperostosis and Osteitis) is proposed for this group of diseases because of the similarity of musculoskeletal manifestations in patients with severe acne and pustulosis. The clinical, epidemiological, pathophysiological, immunogenetic and diagnostic aspects, as well as the management of this syndrome, are reviewed.

Acne Vulgaris↗
PubMed1994

Pyogenic and tuberculous spondylodiskitis (vertebral osteomyelitis) in 80 adult patients.

Bacterial spondylodiskitis--i.e., adjacent vertebral osteomyelitis and diskitis--was studied in 80 adult patients. The infection was due to Mycobacterium tuberculosis in 31 cases (39%) and to pyogenic bacteria in 49 cases (61%). The latter pathogens included gram-negative bacilli in 16 cases (20%), Staphylococcus species in 15 (19%), Streptococcus species in 9 (11%), and Corynebacterium species in 1 (1%); the pathogens in the 8 remaining cases (10%) were not identified. Of the patients with tuberculous spondylodiskitis, 55% came from countries where tuberculosis is endemic (P < .001). Cases due to staphylococci and those due to M. tuberculosis were associated with a high frequency of previous active infection with those respective organisms at any site (47% and 42%, respectively; P < .001) and with a high rate of neurological complications (33% and 32%, respectively; P < .001). Nine patients with pyogenic spondylodiskitis (18%) but only one patient with tuberculous spondylodiskitis (3%) had diabetes mellitus (P < .05). Blood cultures were positive in 23 (56%) of the 41 cases of pyogenic spondylodiskitis due to an identified bacterium. Discovertebral needle biopsy contributed to the bacteriologic diagnosis in 29 (74%) of 39 cases.

Adult↗
PubMed1994

Cytofluorometric analysis of chondrotoxicity of fluoroquinolone antimicrobial agents.

To better understand quinolone-related arthropathy, we conceived an experimental ex vivo model using cell cultures of articular chondrocytes issued from pretreated New Zealand White rabbits (NZW). Juvenile (4- to 5-week-old) NZW were orally dosed with ofloxacin or pefloxacin (300 mg/kg of body weight for 1 day) or with pefloxacin (300 mg/kg for 7 days). Adult (5-month-old) NZW were treated with pefloxacin (300 mg/kg for 1 day). Chondrocytes were enzymatically recovered from cartilage and were analyzed by cytofluorometry using 2',7'-dichlorofluorescein diacetate (DCFH-DA) and dihydrorhodamine 123 (DHR), reflecting cellular respiratory-burst activity, and rhodamine 123 (Rh123) and 10-N-nonyl-acridine orange (NAO), specific for the mitochondrial activity and mass, respectively. A significant increase in the respiratory burst was detected by DCFH-DA and DHR in all treated groups of young animals, compared with untreated control groups. No significant increase of respiratory burst was noted in older treated rabbits. The 7-day treatment resulted in a decrease in mitochondrial uptake of Rh123 and an increase in NAO uptake. Fluoroquinolone arthrotoxicity seems to involve in its early phase the respiratory burst of immature articular chondrocytes.

Animals↗
PubMed1994

Interleukin 6 secretion by monocytes and alveolar macrophages in systemic sclerosis with lung involvement.

Interleukin-6 (IL-6) has been involved in the pathogenesis of inflammatory and/or autoimmune diseases. We characterized the production of IL-6 by blood monocytes and alveolar macrophages (AM) in 11 patients with definite systemic sclerosis (SSc) with lung involvement and in eight normal control subjects. IL-6 levels were determined in serum, bronchoalveolar lavage (BAL) supernatants, monocytes, and AM cell culture supernatants using an ELISA kit. BAL cell analysis evidenced an alveolitis with hypercellularity and increased neutrophils and mast cells absolute counts. Serum and BAL IL-6 levels were low and similar in SSc and control groups. The monocytes of the group with SSc secreted more IL-6 than did the control group, both spontaneously (p = 0.01) and after LPS stimulation (p = 0.0007). Spontaneous secretion of IL-6 by AM tended to be higher in the SSc group than in the control group (p = 0.22). LPS-induced IL-6 secretion by AM was similar in both groups. Our study demonstrates that during SSc lung disease, spontaneous and stimulated IL-6 secretion by blood monocytes is increased, compared with secretion by healthy control subjects. By contrast, IL-6 secretion by AM is normal despite evidence of mild alveolitis.

Bronchoalveolar Lavage Fluid↗
PubMed1994

Interleukin-8 and neutrophils in systemic sclerosis with lung involvement.

We investigated the mechanisms and consequences of neutrophil accumulation in the airspace in 11 patients with systemic sclerosis (SSc) and interstitial lung disease. Seven normal subjects served as controls. We measured total neutrophil elastase burden, elastase activity, and alpha-1-antitrypsin (alpha 1AT) in bronchoalveolar lavage (BAL) fluid and we evaluated the in vitro interleukin-8 (IL-8, a potent chemoattractant for neutrophils) secretion by alveolar macrophages (AM). A mild neutrophil alveolitis was observed in patients when compared with control subjects. Total BAL elastase burden was higher in patients than in control subjects and correlated positively with the percentage of neutrophils in BAL. BAL elastase activity was undetectable in control subjects, but it was detected in all patients but one (mean: 257 +/- 87 mU/L). Spontaneous IL-8 secretion by AM was higher in patients with SSc than in control subjects (518 +/- 115 versus 228 +/- 65 ng/ml, p = 0.04) and positively correlated with the percentage of neutrophils in BAL (r = 0.505). We conclude that (1) the neutrophil could participate in the pathogenesis of SSC lung disease through the release of elastase; (2) the AM could contribute to the influx of neutrophils in the alveolus through the release of IL-8.

Bronchoalveolar Lavage Fluid↗
PubMed1994

[Involvement of the hip in systemic-onset forms of juvenile chronic arthritis. Retrospective study of 28 cases].

The objective of this work was to evaluate the course of hip disease in patients with systemic-onset juvenile chronic arthritis. 59 patients with systemic-onset juvenile chronic arthritis followed-up for a mean of 15 years (+/- 6 years) were studied retrospectively. 28 patients (47.5%) had involvement of the hip. Mean age at onset of symptoms of hip disease was 9.5 years (+/- 5 years). Hip arthritis was always preceded by other manifestations of the disease, including arthritis of other lower limb joints. Mean time interval between onset of the disease and onset of hip symptoms was 6.3 years (+/- 3 years). In 66% of cases, symptoms occurred simultaneously in both hips. Eight of nine patients with initially unilateral hip arthritis subsequently developed arthritis of the other hip; in four patients, less than one year elapsed between involvement of the two hips. Roentgenographic changes were variable and included acetabular protrusion (25%), complex cervico-cephalic and acetabular growth disorders (21%), subdislocation (18%), a short femoral neck with varus deformity (14%), and a long femoral neck with valgus deformity (14%). Avascular necrosis of the femoral head occurred in three patients. Roentgenographic evidence of repair was seen in one patient. Among the ten patients who required surgery, two had corrective osteotomy with adductor tenotomy and eight had total hip arthroplasty (of both hips in six patients) with good short- and medium-term outcomes. After arthroplasty, a single patient required reoperation in the short term, for persistent flexion contracture. Loosening of the acetabular arthroplasty required revision in two patients 5 and 10 years, respectively, after the initial procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Arthritis, Juvenile↗
PubMed1994

[Treatment of acute systemic lupus erythematosus with intravenous infusions of cyclophosphamide. Value and limitations].

Monthly intravenous cyclophosphamide (IVCY) has been a recommended therapy for severe lupus nephritis or neurological flare-ups in lupus patients. But the optimal treatment regimen and duration remains unknown. We report our experience in an open study of 37 patients treated with monthly IVCY. Thirty-four women and 3 men, mean age 35.5 with a mean disease duration of 59 months, with a mean 5.7 ACR criteria for SLE were analysed. 27 (group I) had lupus nephritis (OMS Class III or IV) and 10 had neurological involvement (group II). In group I, after six months of IVCY, a significant improvement was noticed in the UCH-Middlesex clinical index (2.9 pts vs 7.8), the proteinuria (3.12 g/d vs 5.4), complement and split fractions (CH50 98.4 vs 48.9%; C3 877 vs 600 mg/l; C4 177 vs 128 mg/l), the level of anti-DNA antibodies (67.5 vs 775 UI/ml) and the daily dose of steroids (22 vs 44 mg/d). Kidney biopsies showed a reduction of the activity index despite a slight increase of the chronicity index (4.1 vs 6.3 pts and 5.5 vs 3.6 pts). Those results were not maintained at medium and long term. Moreover five patients presented with worsening of renal function during IVCY treatment and two patients relapsed after the end of the treatment. In group II significant improvement was noticed at six months concerning the clinical index (1.77 pts vs 7.17) and the daily dose of steroids, 3 patients died because of cerebral vasculitis refractory to IVCY. Adverse effects are frequent: infectious (25 among 20 patients), hemorrhagic cystitis (2 events in 1 patient), gastrointestinal side effects were common (12/37 patients). Were also noticed: neutropenia (5/37), transient amenorrhea (4/28), drug induced menopausis (2/28). Overall mortality is important (7/37), uneffectiveness of IVCY was noticed in 5 patients, flares occurred in 8 patient during or after stopping treatment. IVCY seems efficacious if given at the very beginning of the flare. Its usefulness is obvious at six months among clinical and biological data in patients with severe lupus nephritis or neurological flare. It seems that long term outcome on the renal function is not modified.

Acute Disease↗
PubMed1994

Serum ferritin and isoferritins are tools for diagnosis of active adult Still's disease.

OBJECTIVE: Still's disease is an acute systemic inflammatory disorder. There are no pathognomonic symptoms or specific laboratory abnormalities. Serum ferritin concentration in rheumatoid arthritis together with some plasma glycoproteins such as alpha 2-glycoprotein and C-reactive protein are part of the response to inflammation. Ferritin in plasma is glycosylated and the sialoglycosylated forms increase its microheterogeneity. Our purpose was to confirm in a large series that high values of ferritin can be found in adult Still's disease (ASD) and to see if a specific isoferritin can be isolated in this disease compared with the other systemic diseases. METHOD: Thirty-one sera were investigated from 11 men and 9 women with ASD and compared with 27 sera from 27 patients with systemic diseases. We studied the course of one case of ASD for 15 months. Serum ferritin was determined by immunoenzymology (Abbott Ferrizin). The isoferritins were investigated by isoelectric focussing and the percentage of glycosylation by affinity for concanavalin A (Con-A). RESULTS: In patients with active ASD, the ferritin levels were higher than in patients with inactive ASD or other systemic diseases: p < 0.001. The glycoforms of ferritin were basic and the proportion of ferritin bound to Con-A was lower than other ASD: p < 0.001. CONCLUSIONS: Serum ferritin levels have a diagnostic value for acute ASD. The study of sialylation and abnormalities in the glycosylation of ferritin helps to discriminate ASD from arthritis or other systemic diseases. In conclusion, the glycoform of isoferritins and the percentage of glycosylation offers an additional tool for the diagnosis of Still's disease.

Adolescent↗
PubMed1993

[Synchronization of plasma exchange and cyclophosphamide in severe systemic diseases. A consecutive study of 10 patients].

Ten patients with severe systemic diseases, including systemic lupus erythematosus (n = 2), polymyositis (n = 2), essential mixed cryoglobulinaemia (n = 2), rheumatoid arthritis vasculitis (n = 3) and Wegener's granulomatosis (n = 1), were treated with 3 consecutive plasma exchanges synchronized with pulse cyclophosphamide. This therapeutic regimen was applied every 4 weeks initially and thereafter every 6 weeks in case of positive response after the first 3 cycles; it was combined in all patients with corticosteroid therapy. The treatment was administered for severe flare-up of the disease in 7 patients and for failure of previous treatments, including corticosteroids, cyclophosphamide and plasmapheresis, in 3 patients. Three kinds of response were observed: lasting complete remission without relapse after synchronization had ceased in 4 patients, partial clinical remission with post-synchronization relapse in 5 patients, and primary failure without any clinical response to treatment in only 1 patient. These results suggest that repeated plasma exchanges synchronized with cyclophosphamide are effective against progressive autoimmune diseases and in cases where conventionally administered immunosuppressive treatments had failed. However, this type of treatment cannot prevent long-term relapses, and only a prospective study can evaluate its success in terms of survival.

Adult↗
PubMed1993

A case of scurvy presenting with cutaneous and articular signs.

This report is on a patient, who presented purpura and hemarthrosis in a context of vitamin C deficiency. This case gives us the opportunity to discuss the differential diagnosis, the clinical features, the pathogenicity and the treatment of this rare condition.

Ascorbic Acid↗
PubMed1993

Antibodies to the constitutive 73-kd heat shock protein: a new marker of mixed connective tissue disease?

PURPOSE, PATIENTS, AND METHODS: This report documents the finding of an elevated titer of IgG reacting with the constitutive bovine 73-kd heat shock protein (HSP) in the serum of patients with rheumatoid arthritis, scleroderma, and mixed connective tissue disease (MCTD). RESULTS AND CONCLUSIONS: Further characterization of antibodies from patients with MCTD showed that the antibodies also recognize the human constitutive 73-kd HSP, but not the inducible 72-kd isoform. Very high levels of antibodies appeared to be specific for MCTD; the differences between levels in patients with MCTD and those in healthy subjects (blood donors) were highly significant (p < 10(-8)), with no values in this group of patients overlapping with those in the controls. This parameter might therefore represent a new diagnostic marker for this disease.

Biomarkers↗