Myasthenia gravis: a long term follow-up study of Swedish patients with specific reference to thymic histology.

Background: Myasthenia gravis (MG) is an autoimmune disorder of neuromuscular transmission. The majority of patients show abnormal thymic histology.

Setting: The study was performed at the Myasthenia Gravis Centre, Karolinska University Hospital, and at the Immunological Research Laboratory, Centre for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.

Raised prolactin levels in myasthenia gravis: two case reports and a study of two patient populations.

Objectives: To describe two patients with myasthenia gravis (MG) and prolactinoma and analyze the associations between MG and prolactin (PRL) levels.

Design: Two case reports and a case-control study of PRL levels in 192 patients with MG.

Participants: The Immunological Research Laboratory, Center for Molecular Medicine, Department of Medicine and the Department of Neurology, Karolinska Institutet, Stockholm, Sweden; St Petersburg Medical Academy for Postgraduate Studies, and St Petersburg State Medical Pediatric Academy, Russia.

Epidemiology of myasthenia gravis: a population-based study in Stockholm, Sweden.

A regional database of myasthenia gravis (MG) patients was used to estimate the prevalence and selected characteristics of the disease in the county of Stockholm, Sweden. The prevalence of MG was 14.1/100,000 (17.

Polymorphisms at - 174 and in the 3' flanking region of interleukin-6 (IL-6) gene in patients with myasthenia gravis.

We examined the bi-allelic polymorphism at - 174 in the promoter region and the polymorphism in the 3' flanking AT rich region of the interleukin-6 (IL-6) gene in Swedish patients with myasthenia gravis (MG) and ethnically matched healthy individuals. There was no association between the polymorphisms and the disease. There was no relation of the polymorphisms to the clinical variables, the thymic histopathologies, the level of serum acetylcholine receptor antibodies or the concentrations of IgG and its subclasses.

Tumour necrosis factor-alpha polymorphism and secretion in myasthenia gravis.

The mechanism behind the association between MHC genes and myasthenia gravis (MG) is not fully understood. In the present study we studied the associations with polymorphisms at HLA-DR3, HLA-B8 and TNF-alpha genes in Swedish patients and healthy individuals. The TNF-alpha-308 allele 2 was associated with female patients having disease onset before the age 40 and with thymic hyperplasia.

Decreased beta2-adrenergic receptor density on peripheral blood mononuclear cells in myasthenia gravis.

Beta2-adrenergic receptors (beta2AR) are present on both lymphocytes and skeletal muscle cells. Antibodies and T cells that react with these receptors are present in patients with myasthenia gravis (MG). Immune reactivity against the beta2AR may thus modify both the immune and the muscle functions in MG.

The effect of thymectomy on autoreactive T- and B-lymphocytes in myasthenia gravis.

Eleven patients with myasthenia gravis were followed for three years after thymectomy. Acetylcholine receptor-specific T-cell stimulation was found in 8/11 patients before operation as compared to 2/11 three years after thymectomy. Changes of T-cell antireceptor-reactivity were commonly paralleled by changes in disease severity.

Acute effects of intravenous injection of beta-adrenoreceptor- and calcium channel at antagonists and agonists in myasthenia gravis.

The effect of intravenous injection of propranolol, verapamil, terbutaline, calcium, and edrophonium on neuromuscular transmission has been studied with repetitive nerve stimulation and clinical tests in 10 patients with myasthenia gravis (MG). The drugs were given intravenously in doses commonly used in clinical practice. Only minor clinical effects were noted except for edrophonium.

T and B lymphocytes reacting with the extracellular loop of the beta 2-adrenergic receptor (beta 2AR) are present in the peripheral blood of patients with myasthenia gravis.

Eighteen percent of patients with myasthenia gravis (MG) have serum antibodies against a synthetic peptide corresponding to the second extracellular loop of the human beta 2AR (residues 172-197). In this study we examined T and B cell responses to the peptide, using assays to detect individual cells secreting interferon-gamma (IFN-gamma) and IL-4 or antibodies against the peptide, and by measuring thymidine incorporation in response to the peptide. The peptide from the beta 2AR induced cytokine secretion from blood mononuclear cells in 67% of MG patients, compared with 14-28% of the control groups.

Evaluation of a knowledge-based decision-support system for ventilator therapy management.

Evaluation of knowledge-based systems differs from that of conventional systems in terms of verification and validation techniques. Furthermore, evaluating medical decision-support systems is difficult because the field is thus far comparatively unexplored. This paper presents an evaluation of a medical knowledge-based system called VentEx that supports decision-making in the management of ventilator therapy.

Factitious disorder presenting with acute cardiovascular symptoms.

A 23-year-old female student exhibited all the characteristics of chronic factitious disorder with physical symptoms (Munchhausen's syndrome): deliberate simulation of illness, peregrination, fantastic pseudology and dramatic circumstances on admittance. The patient induced impressive blood pressure peaks by the Valsalva manoeuvre. She also simulated arrhythmias, seizures and unconsciousness.

Treatment of myasthenia gravis with anti-CD4 antibody: improvement correlates to decreased T-cell autoreactivity.

We treated a patient with severe myasthenia gravis with a chimeric (murine/human) anti-CD4 monoclonal antibody (cM-T412) for 7 days and followed the therapeutic effect by standardized muscle function tests, single-fiber electromyography, and immunologic examinations of disease-specific B- and T-cell functions. Clinical and electrophysiologic improvement began within 4 days, lasted for 3 months, and was maximal between days 16 and 58. The CD4+ lymphocytes decreased to a minimum of 80 cells per microliters of peripheral blood, recovered slowly during the first year of follow-up, and did not correlate with changes in disease severity.

VentEx: an on-line knowledge-based system to support ventilator management.

This paper will demonstrate the clinical application of a knowledge-based decision-support system called VentEx for ventilator management. VentEx has been implemented using a knowledge-based development tool on a PC under the Microsoft Windows multitasking environment. It is integrated into a computer aided ventilator system including the Siemens Elema Servo Ventilator 900 C equipped with a Servo Computer Module 990 and the CO2 analyser 930.

Beta 2-adrenergic receptor antibodies in myasthenia gravis.

Although autoantibodies against the nicotinic acetylcholine receptor are the characteristic feature of the autoimmune disease myasthenia gravis (MG), no strong correlation is found between the autoantibody titer and the degree of clinical severity. Numerous studies have attempted to detect the presence of other autoantibody populations that might have a role in the pathology of the disease. We report, for the first time, that 18% of the MG patients we screened have antibodies in their serum to a peptide corresponding to the second extracellular loop of the human beta 2-adrenergic receptor (residues 172-197).

Kave: a tool for knowledge acquisition to support artificial ventilation.

A decision support system for artificial ventilation is being developed. One of the fundamental goals for this system is the application of the system when a domain expert is not present. Such a system requires a rich knowledge base.

Mechanical ventilation in medical and neurological diseases: 11 years of experience.

Mechanical ventilation (MV) is imperative in many forms of acute respiratory failure (ARF). The aim of this work was to review all episodes of MV in a Medical Intensive Care Unit (MICU) during the 11-year period 1976-1986. Four per cent (n = 1008) of 24,899 admissions to the MICU were treated with MV.

Statistical models for prediction of arterial oxygen and carbon dioxide tensions during mechanical ventilation.

The possibility of constructing statistical models for prediction of alveolar oxygen and carbon dioxide tensions has been investigated in 20 mechanically ventilated patients in acute respiratory failure (ARF). Linear multiple regression analysis using PaCO2 and PaO2 as dependent variables was used to construct (a) models for individual patients, (b) models for specific diagnostic groups and (c) general models (all patients). The coefficient of determination (R2) was highest for the individual patient models (0.

Multivariable optimization of mechanical ventilation. A linear programming approach.

The proposed method aims at improved ventilatory care with reduced morbidity. It combines two important aspects of mechanical ventilation: gas exchange and lung mechanics. A single criterion was selected as optimization index of lung trauma: peak respiratory power (PRP) defined as the maximum product of pressure times flow during inspiration.

Diagnostic utility of flumazenil in coma with suspected poisoning: a double blind, randomised controlled study.

Objective: To assess the diagnostic value and safety of the benzodiazepine antagonist flumazenil in patients with coma of unclear origin with suspected poisoning.

Design: Double blind, placebo controlled, randomised study.

Setting: Intensive care unit at a major teaching hospital.

Integrating knowledge-based technology into computer aided ventilation systems.

A knowledge-based decision support system for respirator treatment, the KUSIVAR system, has been designed in cooperation between hospital, university and industry. Changes in patient data from respirator and monitoring equipment trigger a computer program that generates advice to the staff concerning e.g.

Lung function analysis and optimization during artificial ventilation. A personal computer-based system.

In an intensive care unit a personal computer (PC) application for lung function analysis has been in use for 5 years. The PC system is applied to measure conventional and new parameters for diagnosis and therapy. The primary goal was to find parameters which could be used as optimization indices in optimal control systems for mechanical ventilation.

Different HLA DR-DQ associations in subgroups of idiopathic myasthenia gravis.

We have investigated the HLA-DRB and -DQB gene polymorphism in 131 myasthenia gravis (MG) patients. The HLA genotypes in these patients were assigned by means of restriction fragment length polymorphism (RFLP)-defined DR-DQ haplotypes, correlating to serologic HLA class II typing. Using this technique we could, among randomly selected non-thymomatous (NT)-MG patients, confirm the strong association to DR3, and 70% of the patients were found to carry a specific DR3-positive DR-DQ haplotype, T-3.