Search PubMed⌕ Search

Biomedical subjects

G K Scadding

Publications and source records attributed to G K Scadding.

70 records · Page 4Linked to original sources
PubMed1987

Anti-cardiolipin antibodies in neurological disorders: cross-reaction with anti-single stranded DNA activity.

Antiphospholipid (PL) antibodies have been detected in sera from patients with chronic neurological diseases associated with disorders of immunity. In an isotype specific radioimmunoassay for anti-cardiolipin (CL) antibodies, we found IgM anti-CL (greater than 2 s.d. above mean of controls) in 17/25 (68%) patients with myasthenia gravis (MG), 8/25 (32%) with the Lambert-Eaton myasthenic syndrome (LEMS), 5/17 (29%) with multiple sclerosis and 3/11 (27%) cases of migraine. IgG anti-CL was only found in low titres in sera from 10 patients with MG and three with LEMS. Significant anti-CL activity could not be detected in sera from nine patients with acute Guillain-Barré Syndrome (GBS), 12 chronic cases of epilepsy, 8/9 with oat cell carcinoma and 9/10 with acute stroke. Further tests on 39 sera with the highest anti-CL activity, from all of the above disease groups, showed a significant correlation between IgM anti-CL and IgM anti-ss DNA activities. In a series of competitive inhibition assays six sera from patients with MG were shown to have a proportion of both specific and cross-reactive IgM anti-CL and IgM anti-ss DNA antibodies. Anti-phospholipid antibodies occur in certain neurological diseases, at lower titres than seen in SLE, yet their cross-reactive binding to ss DNA suggests similar antibacterial origins as have been proposed for lupus auto-antibodies. In the absence of overt infection they might reflect a breakdown of tolerance for non-organ specific membrane antigens in diseases with predominantly organ specific membrane bound putative autoimmunogens.

Antibodies, Antinuclear↗
PubMed1986

Low dose sublingual therapy in patients with allergic rhinitis due to house dust mite.

In a double-blind placebo-controlled cross-over trial, low dose sublingual therapy with house dust mite was effective in relieving symptoms in 72% of the group of patients with perennial rhinitis due to house dust mite (P less than 0.03). Following active treatment, there was a significant increase in morning peak nasal inspiratory flow rate (P less than 0.01) in those who improved (thirteen out of eighteen) and resistance to nasal provocation with house dust mite also increased, in some cases up to 1000-fold (P less than 0.05). Oral therapy is safe and avoids the side effects of desensitizing injections which can be serious. The potential for oral desensitization is great and further studies on this form of treatment are needed.

Administration, Oral↗
PubMed1986

Anti-acetylcholine receptor antibodies induced in mice by syngeneic receptor without adjuvants.

Acetylcholine receptor (AChR)-bearing membranes from the BC3H-1 cell lines were injected, without adjuvant, either intrathymically (i.t.) followed by intraperitoneal (i.p.) booster doses, or i.p. alone, into (C57BL X BALB/c)F1 mice. Over 75% of the animals developed serum anti-AChRs which reacted with the cell-line AChR and with normal mouse endplate AChR. The titres were within the lower range of those of myasthenia gravis patients, and some mice showed reduced miniature endplate potential (m.e.p.p) amplitudes. these results indicate that loss of tolerance to acetylcholine receptors can result from immunization against syngeneic AChR without adjuvant. This approach may provide a useful model for studying mechanisms of autoimmunity against acetylcholine receptor.

Action Potentials↗
PubMed1985

The long term experience of thymectomy for myasthenia gravis.

A retrospective survey of the records of 287 patients with generalised myasthenia gravis treated at New End Hospital and later at the Royal Free Hospital by anticholinesterase drugs, with or without thymectomy, between the years 1942 and 1976, shows that 62% of patients were improved. The timing of the operation, the grading of disease and the age and sex of the patient did not greatly influence overall results. The poor diagnosis of thymic tumours was confirmed in this series. A decrease occurred in the number of patients achieving complete remission after 1961, although the proportion of patients improving did not fall. It is possible that anticholinesterase therapy may alter the response to thymectomy.

Age Factors↗
PubMed1983

Myasthenia gravis. Pathogenesis and current concepts in management.

Myasthenia gravis is a disorder of autoimmunity in which neuromuscular transmission is impaired by autoantibodies to the acetylcholine receptor (AChR). There is evidence for more than one form of the disorder with differing genetic susceptibilities. The aetiology is unknown, but thymic involvement is suggested by abnormal histology and by the beneficial response of the disorder to thymectomy in more than two-thirds of patients. Thymectomy is indicated in most patients unless the symptoms are minimal or are confined to the extraocular muscles alone, or the patient is elderly. Thymectomy alone results in remission in about one-third of patients, but, in addition, most patients require symptomatic anticholinesterase drugs to prolong the action of acetylcholine at the muscle end-plate. Over-dosage of these drugs can also cause weakness. Immunosuppression with corticosteroids or azathioprine may also improve myasthenia; at present, these drugs are used mainly in patients who do not respond to thymectomy or in those patients considered unsuitable for operation. Plasma exchange can cause a rapid, though temporary, involvement in myasthenia, but it probably has no long term place in its treatment. Future therapy will probably involve specific immunotherapy, such as anti-idiotype antibodies.

Cholinesterase Inhibitors↗
PubMed1983

Glomerulonephritis, thymoma and myasthenia gravis.

Three patients with myasthenia gravis, in whom a thymoma had been removed during total thymectomy four to 14 years earlier, developed glomerulonephritis presenting as the nephrotic syndrome. All had been treated previously by plasma exchange and were receiving azathioprine. Two were also taking prednisolone. Serum immune complexes containing IgM were present in all three. Renal histology showed either focal segmental glomerulosclerosis, minimal change lesion or focal proliferative glomerulonephritis. No immunoglobulin deposits were seen. Two patients lost their proteinuria on high dose corticosteroid therapy and their renal function improved. Glomerulonephritis occurred in nine per cent of patients with thymoma receiving immunosuppressive treatment with azathioprine for more than two years. We suggest that this treatment may be implicated in its aetiology.

Adult↗
PubMed1981

Acetylcholine receptor antibody synthesis by thymic lymphocytes: correlation with thymic histology.

Antiacetylcholine receptor antibody (anti-AChR) was spontaneously synthesized by cultured thymic tissue from 19 of 35 patients with myasthenia gravis. Two other thymus cultures produced antibody after stimulation by pokeweed mitogen. Antibody production correlated with histologic evidence of thymitis, long duration of symptoms, or high serum anti-AChR values. None of seven thymomas synthesized antibody in culture, but evidence suggested that there had been in vivo synthesis or trapping of anti-AChR. Clinical improvement after thymectomy, during the short period of study, did not correlate with synthesis rates of anti-AChR production by the removed thymus. The rates of anti-AChR production in culture were too low to suggest that the thymus is the major source of this antibody. Although we did not find a clear relationship between anti-AChR antibody and clinical state within 3 months of thymectomy, in a study of 25 nonimmunosuppressed, nonthymoma patients followed for 1 to 4 years, we found a significant correlation (p less than 0.05, Spearman Rank correlation) between fall in anti-AChR antibody and clinical improvement after thymectomy (unpublished observations).

Acetylcholine↗
PubMed1979

Humoral immunity before and after thymectomy in myasthenia gravis.

Humoral immunity was studied in 10 patients with myasthenia gravis before thymectomy, in 15 different patients over 10 years after thymectomy, and in normal controls. Antibody titers to acetylcholine receptor were significantly (p less than 0.01) lower in the post-thymectomy group. However, other antibody titers to common viruses, and to Escherichia coli, and isohemagglutinins showed no significant change. Levels of IgM and IgE (with atopic subjects excluded) decreased following thymectomy (p less than 0.05). Autoantibodies persisted, apart from those directed against the acetylcholine receptor. The absence of any significant changes in humoral immunity after thymectomy for myasthenia gravis suggests that there is no generalized loss of helper T-cell function.

Adult↗
PubMed1979

The immunological effects of thymectomy in myasthenia gravis.

Thymus-derived (T) lymphocytes in the peripheral blood and cellular immune function have been studied in ten patients with myasthenia gravis and in fifteen different myasthenic patients more than 10 years after thymectomy. The results were compared with those of a normal control population. The non-thymectomized myasthenic patients had normal T lymphocyte concentrations measured by rosetting with native sheep red cells. These patients also showed normal sensitization and recall of delayed hypersensitivity, phytohaemagglutinin (PHA) induced lymphocyte transformation and antibody-assisted (K cell) cytotoxicity; however, PHA-induced cytotoxicity was markedly reduced (P less than 0.001). The thymectomized group exhibited a lower mean percentage and absolute number of E-rosette-forming cells, which returned toward normal after in vitro treatment with thymosin. PHA-induced lymphocyte cytotoxicity, however, was normal in the patients who had undergone thymectomy, as were lymphocyte transformation, antibody-assisted cytotoxicity and sensitization to dinitrochlorobenzene (DNCB); there was a decrease in recall of established delayed hypersensitivity. Adult thymectomy in man, therefore, produces a partial and dissociated decrease in T cell responses and it is unlikely that the beneficial effect of this operation in myasthenia gravis is related to immunosuppression.

Adolescent↗
PubMedDate not supplied

The in vitro effects of D-penicillamine upon anti-AChR production by thymic and peripheral blood lymphocytes from patients with myasthenia gravis.

D-Penicillamine added to lymphocyte cultures from myasthenia gravis patients infrequently and inconsistently stimulated anti-AChR production. This usually occurred in the presence of pokeweed mitogen (PWM), and often only at a single concentration of D-penicillamine which varied among patients. The change was typically paralleled by an increase in total IgG production of similar magnitude, suggesting that the effect was nonspecific. D-penicillamine did not affect AChR expression in cultured thymic adherent cells. These data provide no evidence that penicillamine induces myasthenia gravis by direct stimulation of anti-AChR antibody-producing cells.

Adolescent↗
PubMedDate not supplied

The effect of endoscopic sinus surgery on asthma: management of patients with chronic rhinosinusitis, nasal polyposis, and asthma.

We attempted to determine the efficacy of endoscopic sinus surgery in adult patients with asthma and chronic rhinosinusitis or nasal polyposis. Fifty asthmatic patients from 17 to 74 years of age with a history of either chronic rhinosinusitis or nasal polyposis were examined. Sinonasal disease was confirmed endoscopically and with computerized tomography, and all had failed aggressive medical management of their sinonasal disease before undergoing endoscopic sinus surgery performed by the same surgeon in all cases. The following were compared for 12 months: preoperative and postoperative overall asthma control, peak flow measurements, asthma medication requirements, including the use of oral steroids, and hospitalizations for asthma. Twenty patients felt that their asthma control had improved postoperatively. Twenty per cent used less steroid inhaler, and 28% less bronchodilator inhaler. Of those 23 patients measuring peak flows, seven achieved higher levels and seven noted fewer dips and swings. Significant reductions in oral steroid requirements (p < 0.001) and hospitalization for asthma (p < 0.025) were also recorded postoperatively. Irrespective of whether the patient had chronic rhinosinusitis or nasal polyposis, both groups improved postoperatively. The commonest symptoms experienced by the group as whole and by the nasal polyposis patients were hyposmia and nasal obstruction. Postnasal discharge and headache were more important in the chronic rhinosinusitis group. Mean visual analog scores improved for all symptoms; in particular for nasal obstruction and sense of smell. Aggressive management of sinonasal pathology can improve asthma status. No major differences were recorded for outcomes when comparing patients with chronic rhinosinusitis or nasal polyposis; in particular there was no evidence for a worsening of asthma after nasal polypectomy.

Administration, Oral↗
PubMedDate not supplied

The upper airway.

Explore the source record for details and available documents.

Humans↗