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Biomedical subjects

R M Krause

Publications and source records attributed to R M Krause.

At least 19 recordsLinked to original sources
PubMed1992

The origin of plagues: old and new.

Viruses and bacteria emerge in new and old forms to cause disease epidemics. Some microorganisms recur when changing life-styles (including increased international travel) offer new opportunities; others arise from new genetic variations. These various epidemics connect the future with the past, offering lessons for guarding the health of generations to come--lessons learned from diseases such as tuberculosis, toxic shock syndrome, Lyme disease, streptococcal infection, influenza, and acquired immunodeficiency syndrome (AIDS). The public must be vigilant to the possibility of new epidemics, learn more about the biology and epidemiology of microbes, and strengthen systems of surveillance and detection.

Acquired Immunodeficiency Syndrome↗
PubMed1979

Detection of antibodies in human sera to streptococcal groups A and C carbohydrates by a radioimmunoassay.

Human antibodies to streptococcal groups A and C carbohydrates were measured quantitatively with a radioimmunoassay using tyrosylated 125I carbohydrate. Analysis of acute and convalescent sera from people with groups A or C streptococcal pharyngeal infection or persistent carriage revealed a significant rise in antibodies. Inhibition reactions with the cold carbohydrate indicated the specificity of the elicited antibodies. In some instances, group C as well as group A antibodies occurred after group A pharyngeal infections. Further clinical and epidemiological studies are required to determine the significance of group-specific antibodies. Antistreptolysin-O (ASO) rises were observed in individuals with group C antibody responses after persistent group C pharyngeal carriage. For this reason, epidemiological surveys that rely primarily on ASO surveys to determine the incidence of group A streptococcal infections must be interpreted with caution, at least in the developing countries, where group C pharyngeal carriage is common.

Antibodies, Bacterial↗
PubMed1976

Detection of antibodies to bacterial cell wall peptidoglycan in human sera.

A radioimmunoassay has been developed for the measurement of antibodies to peptidoglycan in human sera including patients with rheumatic fever and juvenile rheumatoid arthritis. The assay is based on the percentage of binding of the hapten 125I-L-Ala-gamma-d-Glu-L-Lys-D-Ala-D-Ala, the major peptide determinant of peptidoglycan. Because of differences in the avidity of the antibodies in different sera, the amount of antibody was expressed as pentapeptide hapten-binding capacity (pentapeptide-HBC in ng/ml of serum). Fourteen out of 105 normal blood donors had a pentapeptide-HBC value greater than or equal to 75 ng/ml serum. Values in healthy children 5 to 18 years of age were less than or equal to 50 ng/ml. Sixty-eight percent of the individuals with rheumatic fever had values greater than or equal to 75 ng/ml, an indication that streptococcal infections can stimulate an immune response to peptidoglycan. Thirty-five percent of the patients with juvenile rheumatoid arthritis had values greater than or equal to 75 ng/ml. Such a finding points to a possible association between bacterial infections and juvenile rheumatoid arthritis.

Acute Disease↗
PubMed1975

Primary structure of the L chain from a rabbit homogeneous antibody to streptococcal carbohydrate. I. Purification of antibody and sequence determination of peptides from alpha-chymo-tryptic and thermolytic digests.

Primary structural studies have been carried out on the light chain of a homogeneous rabbit antibody to Group C streptococcal carbohydrate. Approximately 20 g of this antibody were obtained by multiple exchange transfusions at the peak of the antibody response. The isolated antibody was homogeneous by several antigenic and chemical criteria. The light chain was isolated and modified, and then digested with alpha-chymotrypsin or thermolysin. The resulting peptides were isolated by gel filtration, paper electrophoresis, and paper chromatography. The amino acid sequences of these peptides were determined by Edman degradation plus dansylation. This supplied sufficient information to assign approximately 90 percent of the residues in the chain. The destruction of tyrosine during acid hydrolysis of peptides which had been eluted from a paper chromatogram was investigated. This destruction is due to inpurities in the paper which contaminate the peptides. Prevention of such destruction can be achieved by predevelopment of the paper with 1 N NH4OH prior to paper chromatography.

Amino Acid Sequence↗
PubMed1975

Prevention of streptococcal sequelae by penicillin prophylaxis: a reassessment.

In conclusion, the diagnosis of streptococcal infection lacks precision, and as long as this is so, reliance must be placed on trained clinical judgement together with bacteriological studies. There is some evidence for an evolutionary drift in the relationship between the streptococcus and man, a drift that is compatible with the natural history of other diseases and with the accomodations observed in nature among other species during the course of evolutionary events. If, as a result of recent accomodations between man and the group A streptococcus, the risk of rheumatic fever is less, an undefinable risk nevertheless remains. There was even a military outbreak of rheumatic fever in England several years ago, and on that island--we are told--rheumatic fever has been banned for years. The current recommendations of the American Heart Association for the secondary prevention of rheumatic fever I judge acceptable for use in the United States. I have, however, raised the possibility that they may be inadequate for the prevention of second attacks in other populations where the environmental, socioeconomic, bacteriological, and nutritional circumstances are different from our own. Studies designed to reexamine these questions may, in the end, refocus our attention on the importance of host factors in the occurrence and pathogenesis of rheumatic fever.

Developing Countries↗
PubMed1975

Newly recognized distinctive M protein associated with certain M type 1 group A streptococci.

Immunological and epidemiological characteristics of M1T1 and M1T8 (T8, 25, Imp.19) group A streptococci isolated in Egypt have been described. Both strains possess a common M1 antigen. The M1T8 strains possess a second antigen which has the immunological and biological characteristics of M protein. The M1T1 strains do not possess this second M antigen. Absorbed rabbit antisera which are specific for this second antigen do not react with extracts of any of the known M protein serotypes. This second antigen is therefore a newly recognized M protein. The M1T1 and M1T8 strains had mutually exclusive geographical and temporal distributions. This finding may have been a consequence of the immunity which occurred after the initial occurrence of the M1T8 strain.

Absorption↗
PubMed1975

Use of radioimmunoassays to determine the concentration of streptococcal group-specific antibodies in rabbit antisera.

A radioimmunoassay was developed for the quantitation of antibodies to the Group A, A-variant, and C carbohydrates in rabbit streptococcal antisera. The assay employs radiolabeled purified Group carbohydrate which has been tyrosylated to allow for incorporation of 125-I. This assay has an advantage over the intitative precipitin test because it measures non-precipitating antibody in addition to precipitating antibody. Furthermore, 7S anti-IgG in rabbit antisera give a falsely elevated value for the antibody concentration in the quantitative precipitin test. This did not occur with the radioimmunoassay. The assay described is reproducible, sensitive, and uses little antisera.

Adsorption↗
PubMed1975

A radioactive hapten-binding assay for measuring antibodies to the pentapeptide determinant of peptidoglycan.

A major portion of the humoral immune response to peptidoglycans is directed against the non-cross-linked pentapeptide side chains of these ubiquitous bacterial antigens. At present, no specific and sensitive assay for pentapeptide antibody determination is available. Therefore, a radioimmunoassay has been developed which employs the synthetic pentapeptide hapten L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala, labeled by the active ester method of Bolton and Hunter to high specific activities (6.74 to 18.18 muCi/mug) with 125I, and used as a reagent for measuring pentapeptide antibody. A-variant streptococcal antisera, known to contain pentapeptide antibodies as shown by quantitative precipitation, would bind more than 95% of the radiolabeled hapten in contrast to 2 to 3% by preimmune rabbit sera. Specificity of the binding reaction was demonstrated by inhibition experiments imploying various synthetic oligopeptides related or unrelated to the pentapeptide in the radioimmunoassay. Binding curves established with serial dilutions of peptidoglycan antiserum were linear from 15 to 500 mug/ml of antibody permitting pentapeptide antibody measurement within this range. Comparative data on pentapeptide antibody determinations by quantitative precipitation and radioimmunoassay are given and the time course of the production of this antibody in 14 rabbits hyperimmunized with A-variant streptococcal vaccine is reported.

Ammonium Sulfate↗