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S Jonsson

Publications and source records attributed to S Jonsson.

At least 55 records · Page 3Linked to original sources
PubMed1982

Cardiac arrhythmias in hypertrophic cardiomyopathy.

This study was designed to assess the prevalence of cardiac arrhythmias in a group of relatives of patients who had come to necropsy with hypertrophic cardiomyopathy. Another aim of the study was to assess the validity of an interventricular septal thickness of 1.3 cm or more, measured by echocardiography, as a diagnostic criterion of hypertrophic cardiomyopathy among relatives of cases proven at necropsy. Fifty close relatives of eight deceased patients were examined. By the above definition 22 relatives had hypertrophic cardiomyopathy and 28 did not. A comparison of the prevalence and types of cardiac arrhythmias, as shown by 24 hour ambulatory electrocardiographic monitoring, was made between the two groups and a third apparently healthy group of 40 people. The patients with hypertrophic cardiomyopathy showed a significant increase in supraventricular extrasystoles/24 hours, supraventricular arrhythmias, high grade ventricular arrhythmia, and the number of patients with more than 10 ventricular extrasystoles every 24 hours when compared with the other groups. There was no significant difference between normal relatives and controls. The prevalence and types of arrhythmia in these patients were similar to those found by other investigators using different diagnostic criteria. These results support the contention that these patients do indeed have hypertrophic cardiomyopathy and suggest that all close relatives of necropsy proven cases should be examined by echocardiography and subsequently by ambulatory electrocardiographic monitoring if the interventricular septal thickness is 1.3 more.

Adolescent↗
PubMed1981

A procedure for removing high titer antibodies by extracorporeal protein-A-sepharose adsorption in hemophilia: substitution therapy and surgery in a patient with hemophilia B and antibodies.

A 37-yr-old hemophiliac with factor IX antibody in high titer required operation for a pseudotumor growing invasively into the bone in his left elbow. Exchange plasma-pheresis was not feasible, mainly because of possible stimulation of factor IX inhibitor. In addition, the patient had antibodies against tissue antigens. The factor IX antibodies were of IgG type and adsorbable to protein-A-agarose. The antibodies were removed by extracorporeal adsorption of the plasma (separated intermittently in a cell centrifuge) to sterile protein-A-Sepharose in columns, operated by a computer. The treated plasma was retransfused. In this manner, a total of 6000 ml of plasma was depleted of antibodies, and the antibody titer, as well as the total immunoglobulin content, decreased to one-fifth of the original values. The remaining antibodies were neutralized by infusion of factor IX concentrate. Conventional substitution therapy, in combination with immunosuppression, was then possible. The operation was performed without complications. No signs of hemolysis, complement activation, or activation of the coagulation system occurred. In principle, the same form of treatment can be used in patients with other forms of antibodies.

Absorption↗
PubMed1980

New bacterial absorption method for determination of hepatitis A IgM and IgA antibodies.

Antibodies against hepatitis A virus (anti-HAV) can be determined by a commercially available radioimmunoassay (RIA) (HavabTM, Abbott). To discriminate between recent and past hepatitis A infection this RIA was used in combination with absorption with protein A-containing staphylococci. However, nonabsorbable anti-HAV was repeatedly detected in late-convalescent sera using this methods. The nature of these antibodies was studied in serum samples from 12 such patients. In all patients, the late-convalescent sera contained no IgM class anti-HAV as judged by sucrose density gradient centrifugation. The restricted specificity of staphylococcal protein A explains the lack of absorption. Some recently described streptococcal strains capable of binding all IgG subclasses (including IgG3) as well as both IgA subclasses were, therefore, added to the staphylococci. Absorption studies using these strains indicated that the previously nonabsorbable anti-HAV in these 12 patients was mainly of the IgA class. A bacterial mixture including IgA-binding streptococci seems preferable to routine determination of IgM anti-HAV in acute hepatitis A diagnosis. The results also indicate that IgA anti-HAV in serum can persist for more than two years after a hepatitis A infection.

Absorption↗
PubMed1979

Specific absorption of human serum albumin, immunoglobulin A, and immunoglobulin G with selected strains of group A and G streptococci.

Five gram-positive bacterial strains were selected for absorption studies of human serum samples. Strain AR1 (group A, M-type 1) and G148 (group G), with strong immunoglobulin G (IgG) binding capacities, and strain AW43 (group A, M-type 60), binding both IgA1 and IgA2, were compared with Staphylococcus aureus Cowan I and with Staphylococcus epidermidis L603. Both AR1 and G148 were capable of completely absorbing out serum IgG. In contrast, S. aureus Cowan I left a fraction unabsorbed, as expected from its known lack of IgG3 binding. Strain AW43 absorbed out all serum IgA, using a 10-microliter bacterial pellet for 20 microliter of serum. Serum IgM levels were slightly reduced by S. aureus Cowan I absorption. On the basis of the experiments, a bacterial mixture was designed consisting of S. aureus Cowan I and group A streptococcus strains AR1 and AW43, with absorption characteristics suitable for use in discriminating between early IgM and late IgG and IgA immune responses in routine serological work. A new type of bacteria-mammalian protein binding was discovered. Human serum albumin was completely absorbed out by strain G148 and to a lesser extent by strain AR1 and AW43. S. aureus Cowan I and S. epidermidis were negative. The binding capacity of G148 for albumin equalled that of Cowan I for IgG. The binding pattern of albumin to the strains was different from those of IgG, IgA, IgM, fibrinogen, haptoglobin, or aggregated beta 2-microglobulin and therefore seems to represent another type of bacterial-mammalian interaction with a specific albumin receptor on the surface of streptococci.

Absorption↗
PubMed1978

Non-equilibrium enzyme immunoassay of gentamicin.

We describe a fast, accurate non-equilibrium enzyme immunoassay for serum gentamicin. With use of isokinetic conditions an assay takes a total of 12 min, including regeneration of the immunosorbent. The coefficient of correlation between the present method and conventional microbiological assays was 0.98.

Catalase↗
PubMed1973

New method for the serological grouping of Streptococci with specific antibodies adsorbed to protein A-containing staphylococci.

A coagglutinating reagent has recently been developed and utilized in capsule typing of pneumococci. The reagent consists of stabilized staphylococci coated with specific antibody via the gamma globulin Fc-protein A reaction thereby orienting the antibody molecules with the antigen-reactive Fab parts outwards. Reagent staphylococci coated with antibodies directed against streptococcal group-specific antigens have been used in the present investigations. Overnight cultures of streptococci were treated with trypsin and then directly tested for coagglutination of selected reagent staphylococci on glass slides. In all, 179 strains of streptococci were analyzed by the method described. The results were compared with grouping by using Lancefield extracts in counter-immunoelectrophoresis and were shown to agree completely. The coagglutination method described proved to be accurate, rapid, and simple.

Adsorption↗