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Biomedical subjects

J Oger

Publications and source records attributed to J Oger.

At least 55 records · Page 3Linked to original sources
PubMed1988

Multiple sclerosis: a serial study using MRI in relapsing patients.

Prospective monthly magnetic resonance imaging (MRI) studies were done over 6 months in seven relapsing MS patients. MRI and neurologic evaluations were compared for sensitivity in detecting disease activity. Four patients were clinically stable throughout the study. Three patients had five clinical relapses, two localized to the spinal cord and three to the brainstem. Eighteen new and ten enlarging MRI lesions were seen in five patients. Most lesions were less than 10 mm in diameter. All were clinically silent. Two patients developed major enlarging MRI lesions (seen in three slices) which increased in size over 2 months and then gradually became smaller over 2 months, leaving behind small residual areas of abnormality. There were 36 follow-up scans, 17 of which (47%) showed evidence for increasing activity. Thirteen (36%) of the scans had new lesions, most of them being small. This study shows that MRI evidence for disease activity in MS is much more frequent than is clinical evidence.

Adult↗
PubMed1988

Multiple sclerosis: in relapsing patients, immune functions vary with disease activity as assessed by MRI.

We have serially studied immunoglobulin G secretion in vitro, natural killer cell function, and concanavalin A-induced suppression in a group of seven patients with relapsing-remitting multiple sclerosis. In two patients, the development of a large clinically asymptomatic MRI lesion was accompanied by reductions in natural killer cell function, immunoglobulin G secretion in vitro (after pokeweed mitogen stimulation), and concanavalin A-induced suppression without parallel change in lymphocyte markers. We did not see this type of change in matched controls nor in stable multiple sclerosis studied serially. When clinical attacks appeared, there was no significant change in immune function. We conclude that changes in immune function correlate well with the activity of the disease as recognized by MRI. We suspect that decreased natural killer cell function, immunoglobulin G secretion in vitro, and concanavalin A-induced suppression are secondary to the large lesions recognized by MRI.

Adult↗
PubMed1988

Antibody production by blood lymphocytes in myasthenia gravis: reduction in disease of long duration.

We measured acetylcholine receptor antibody (AchR Ab) and IgG secreted in vitro by blood lymphocytes from myasthenia gravis patients and controls. Eleven of 20 patients secreted AchR Ab. Controls did not secrete AchR Ab. IgG secretion was lower in patients who were nonsecretors of AchR Ab (351 +/- 127 ng/ml/10 days) than in secretors (3,563 +/- 949) and both groups differed from controls (1,305 +/- 353). Absence of secretion of AchR Ab and low IgG secretion correlated with long disease duration. The data suggest that nonspecific suppression of B cell mediated immune function may occur in long-standing myasthenia gravis.

Antibody Formation↗
PubMed1987

Acetylcholine receptor antibodies in myasthenia gravis: use of a qualitative assay for diagnostic purposes.

We have modified the techniques of Lindstrom and of Tindall to measure serum acetylcholine receptor antibody using human antigen bound to 125I-alpha Bungarotoxin. By using 10 microliters of serum and precipitating antigen-antibody complexes with an excess of staph A, we found that only one out of 43 patients with clinically diagnosed active generalized Myasthenia Gravis had no antibodies. In pooling these results with the results of tests done for diagnostic purposes we found positive results in 54/55 generalized active MG, 8/21 MG in remission, 16/37 ocular MG and 0/55 healthy controls. Two out of 38 non MG were also positive and their clinical diagnosis of botulism and penicillamine treated rheumatoid arthritis have been confirmed by a one year follow-up. Most of these sera were also tested for reactivity with fetal calf AchR. Six out of 49 samples positive with the human receptor were negative with calf receptor. We conclude that our technique is extremely useful for the diagnosis of Myasthenia Gravis and that fetal calf antigen cannot replace human antigen in the assay.

Animals↗
PubMed1987

Reduction of immunoglobulin G secretion in vitro following long term lymphoblastoid interferon (Wellferon) treatment in multiple sclerosis patients.

Pokeweed-mitogen-induced IgG secretion, Con A suppression and T cell surface markers were measured in 30 chronic progressive multiple sclerosis (MS) patients and 21 healthy controls. Mean IgG secretion was higher in the MS patients than in the controls (2392 +/- 270 vs 1499 +/- 243); Con A suppression was lower (4 +/- 5% vs 24 +/- 4%) and the CD4/CD8 ratio was higher (4.1 +/- 0.4 vs 2.9 +/- 0.4). The above assays were used in vitro to monitor the effects of Wellferon (lymphoblastoid interferon) injections on this group of MS patients. Before treatment the INF-group (n = 14) did not differ from the PLA-group (n = 16). After 1 week of daily injections the level of IgG secreted was dramatically reduced in the INF group (629 +/- 96 ng/ml) compared to the PLA-group (1756 +/- 319 ng/ml). There was no change in either Con A suppression or T cell surface markers. IgG secretion remained lower in the INF-group for the 6 month treatment period. Following cessation of the injections and a 6 month washout period, IgG secretion in the INF-group rose and was equivalent to that observed in the PLA-group. A series of lymphocyte subset mixing experiments implicates the B lymphocyte subset as being directly affected by interferon injections in vitro.

Concanavalin A↗
PubMed1986

Fluorescence-activated cell sorter analysis of bulk-isolated porcine oligodendrocytes.

We describe here the methods by which enriched populations of oligodendrocytes were isolated from adult porcine brains using Percoll density gradient centrifugation and their immunological properties analyzed by a fluorescence-activated cell sorter (FACS). The analyses by immunofluorescence microscopy and FACS indicated 95% and 93% purity of oligodendrocytes in the cell preparations when galactocerebroside antibody, an oligodendrocyte-specific marker, was employed. Further FACS analysis indicated that 90% of the cells with the forward angle light scatter characteristics of oligodendrocytes were immunolabelled by the monoclonal antibody HNK-1. The FACS sorting capability was then used to correlate the forward angle light scatter and propidium iodide uptake characteristics of our cell preparations to cell debris, erythrocytes as well as viable and non-viable oligodendrocytes. By gating on a multiparameter basis on both defined forward light scatter and positive galactocerebroside immunolabelling, oligodendrocyte populations exceeding 98% purity were obtained which were suitable for long-term culture and further immunological and neurobiological studies.

Animals↗
PubMed1986

Progressive multiple sclerosis: abnormal immune functions in vitro and aberrant correlation with enumeration of lymphocyte subpopulations.

In a series of 27 consecutive progressive multiple sclerosis (MS) patients under age 50 we have simultaneously measured 3 in vitro immune functions and 6 markers and compared their results to a group of 21 controls. We have confirmed a reduction of concanavalin A (Con A) -induced suppression and NK function contrasting with increased IgG secretion in response to pokeweed mitogen (PWM). Among 6 monoclonal antibody-recognized subpopulation (Leu 1, Leu 2, OKT8, Leu 3, Leu 7 and Leu 11) only Leu 2+ lymphocytes were statistically reduced. OKT8+ were slightly reduced, Leu 3+ were slightly increased. Discriminant analysis revealed that the 3 immune functions together with the results of OKT8 and Leu 3 enumeration were sufficient to appropriately classify most of the individuals. Only 3 MS and 4 controls were misclassified. Correlation analysis suggested disappearance of the doubly labelled OKT8/Leu 7 population in MS patients. In MS as opposed to controls Con A-induced suppression did not correlate with suppressor cell markers but correlated with NK cell markers suggesting that in MS this population mediates Con A-induced suppression. IgG secretion and Con A suppressor cell function were inversely correlated in MS patients but not in controls, suggesting that in chronic progressive multiple sclerosis a common abnormality underlies both increased response to PWM and decreased induction of suppression by Con A.

Adult↗
PubMed1984

[Long-term immunosuppression in multiple sclerosis: evaluation of treatments begun before 1972].

Multiple sclerosis patients have been continuously treated by azathioprine. Only severe progressive forms were selected. The protocol of inclusion and follow-up is detailed. All cases started before 1972 have been reviewed, i.e. 102 cases. Of these 102, 35 stopped azathioprine during the first years and the reasons for this drop-out are analysed. Sixty seven treatments have been maintained for more than 5 years. An evaluation of these 67 patients through the Kurtzke scale shows that the 40 cases with a remittent progressive course have been stabilized as long as they were under treatment. Relapses were observed after discontinuing the therapy. In such cases azathioprine was restarted, leading again to stabilization. Twenty seven cases following a continuous progressive course at the time azathioprine was started showed no evidence of a benefit and kept on worsening. Complications related to treatment (as observed on 240 patients from 1967 to 1982) are detailed with special reference to infections, liver disease and malignancy. Even if the results observed on the course of severe remittent progressive forms of MS are in favor of continuous therapy by azathioprine, this should not be extended to all cases of MS at their first manifestation. It has to be limited to rapidly worsening cases, appreciated after a period of evaluation, when a threatening loss of autonomy may justify some limited risks.

Adrenal Cortex Hormones↗
PubMed1983

[Epidemiology of multiple sclerosis in Brittany].

In the period 1976-1978 a study of the prevalence of multiple sclerosis in Brittany was conducted using data collected from hospital neurology units, Social Security offices and institutions for chronic patients. After elimination of double entries, analysis of these data showed a prevalence of 25 for 100 000 people. This was less than expected from estimates for northern France and from the known prevalences in the southern part of the British isles. When broken down according to the patients' place of residence, the figures were found to vary from one district to another, with four main foci: two near the coast, one inland and one in the town of Fougères. Disease-free areas were present near these foci.

Climate↗
PubMed1983

Immunology of multiple sclerosis.

Evidence points to the conclusion that abnormal regulation of the immune response in MS contributes to ongoing immune activity.

Antibody Formation↗
PubMed1981

[Disseminated sclerosis. Possible correlation between clinical forms and HLA groups (author's transl)].

The study concerns HLA typing of 261 patients with disseminated sclerosis. All patients were grouped for loci A and B. In addition, 94 were typed in HLA DR and 132 in mixed lymphocytic culture (DW2 only). Analysis of tissue group distribution among patients compared with a control population showed not only over-representation of the B7, DW2, A3 B7 and B7 DR2 types (as previously stressed by several workers), but also of A9 and of B8 DR3 and A1 B8 DR3 associations. Moreover, it would seem that there are two distinct clinical forms of disseminated sclerosis, each form being characterized by a specific antigenic HLA association. Side by side with the conventional and most common "remittent" form, which is partly responsive to treatment, has a relatively favourable course and is frequently associated with B7 and DW2/DR2, there appears to emerge around DR3, B8 DR3 and A1 B8 DR3 a rarer, "progressive" form of rapidly increasing severity and resistant to immuno-suppressants. This, however, is a mere hypothesis which needs to be confirmed by further studies on a larger scale.

Female↗
PubMed1980

Autosomal dominant cerebrovascular amyloidosis: properties of peripheral blood lymphocytes.

Selected properties of peripheral blood lymphocytes (PBLs) from five ambulatory affected individuals of a kindred with autosomal dominant cerebrovascular amyloidosis were studied. The percentage of PBLs bearing surface membrane immunoglobulin (SmIg+ cells) was increased in the patient group (30 +/- 3% versus 20 +/- 2%; p less than 0.05). The percentage of PBLs forming early and total E-rosettes was comparable in patient and control groups. Mitogenic response to concanavalin A (Con A) was suggestively reduced in the patient group, measured both by total 3H-thymidine incorporation and by comparison of stimulation indices. Mitogenic response to phytohemagglutinin and pokeweed was comparable in the two groups. Capping of Con A by PBLs was significantly reduced in the patient group compared with the controls (13 +/- 1% versus 26 +/- 2%; p less than 0.01). The findings of reduced Con A response and increased SmIg+ cells support the hypothesis that immune dysfunction contributes to the development of amyloidosis. The reduced capping suggests altered membrane properties in this autosomal dominant disorder.

Adult↗
PubMed1979

[Uveitis and multiple sclerosis: myth or reality?].

The authors have examined three hundred cases of sclerosis (prospective study of an hundred patients, retrospective study of two hundred observations) in order to assess the frequency of uveitis during the disease and to make out a possible relation between the two diseases. The percentage of uveitis is small: 2% and the frequency of uveitis in multiple sclerosis appears not different of that of a normal population. In spite of the simularity of the pathogenic hypothesis, it does not look that a correlation may be made between the two diseases.

Adult↗
PubMed1978

Appraisal of the PAM cell effect as a diagnostic test for multiple sclerosis.

The selective reduction of PAM cell yield reported by Carp and associates in the presence of tissue from patients with multiple sclerosis (MS) has been attributed to replication in culture of a viral agent associated with MS (MSAA). We investigated the diagnostic potential of the PAM cell effect in MS and in optic neuritis (ON). Six serum and 7 CSF samples from 7 patients with MS, 3 serum and 3 CSF samples from 4 patients with idiopathic ON, and 4 sera from 4 patients with ON induced by ethambutal toxicity were tested. Blind counting showed no reduction in PAM cell yield in the MS group nor any significant difference between the two ON groups. Disturbing inconsistencies in PAM cell growth rates over time and between control flasks were demonstrated.

Cells, Cultured↗