Post-streptococcal glomerulonephritis in Hong Kong.
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Of 74 paediatric inpatients with acute glomerulonephritis, 58 (78%) had a raised (greater than 1/200) antistreptolysin O titre. Serum C3 concentration was low in 73, but returned to normal within six weeks. Streptococcal infection remains the commonest cause of acute nephritis in children in Hong Kong, possibly due to overcrowded living conditions. (+info)
Diagnosis of pneumococcal pneumonia by enzyme-linked immunosorbent assay of antibodies to pneumococcal hemolysin (pneumolysin).
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An enzyme-linked immunosorbent assay (ELISA) with a highly purified pneumolysin as the antigen was evaluated for serological diagnosis of pneumococcal pneumonia. One hundred four healthy controls were tested, and the specificity of the test was set to 95%. In samples from patients with bacteremic pneumococcal pneumonia, 82% (18 of 22) were positive, i.e., at least one serum sample had a titer above the upper normal limit or at least a twofold rise in antibody titers was noted. In nonbacteremic pneumococcal pneumonia, 45% (21 of 47) of samples were positive. All sera were negative for patients with pneumonia caused by Haemophilus influenzae, Legionella pneumophila, Chlamydia psittaci, and influenza A virus. However, in patients with a diagnosis of Mycoplasma pneumoniae infection, 8 of 25 (32%) samples were positive for antibodies to pneumolysin. All sera, including those from patients with mycoplasma infection, were negative to a protein control antigen by ELISA. Serum immunoglobulin G response to pneumolysin as measured by ELISA might thus be an aid in the laboratory diagnosis of pneumococcal pneumonia. This assay may also help to further elucidate the occurrence of dual infections with pneumococci. (+info)
Use of available dosage forms of cephalexin in clinical comparison with phenoxymethyl penicillin and benzathine penicillin in the treatment of streptococcal pharyngitis in children.
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The effectiveness of cephalexin, an oral cephalosporin using a dosage equivalent to available capsular dosage forms, was studied in relation to the effectiveness of phenoxymethyl penicillin and benzathine penicillin in the treatment of 128 patients with beta-hemolytic streptococcal pharyngitis, all but six of whom had group A streptococci isolated from throat cultures. Approximately one-half, 66 patients, received cephalexin for 10 days; 34 patients received phenoxymethyl penicillin for 10 days; and 28 patients had a single injection of benzathine penicillin. There were four treatment failures determined bacteriologically post-therapy, two in the cephalexin treatment group and one each in the oral penicillin and intramuscular penicillin groups. Similar cure rates of 96.7, 97.1, and 96.4% were computed for the respective treatment regimens. Whereas intramuscular benzathine penicillin remains the regimen of choice in most instances, cephalexin appeared to be as effective as oral penicillin in the elimination of group A streptococci from the pharynx when oral treatment was desired for streptococcal pharyngitis. (+info)
Biological activity of the cleavage product of human immunoglobulin G with cyanogen bromide.
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Treatment of human IgG with cyanogen bromide in 0.05 M HCl under specified conditions resulted in the cleavage of about half of its methionyl peptide bonds. A major fragment of about 5S was isolated from the reaction mixture by gel filtration in quantitative yield. The CNBr fragment reacted fully with goat antiserum against human light chain, but its reaction with anti-heavy chain was markedly decreased. The treatment with CNBr caused a drastic decrease in the following biological activities of IgG: complement fixing, skin binding, reaction with antiglobulin factors, and reaction with specific anti-Gm(12) serum. On the other hand, the reaction with serum of anti-Gm(1) or anti-Gm(4) specificity was not impaired and antibody activity, namely antistreptolysin and isohemagglutinin, was retained after the treatment with CNBr. It is concluded that the CNBr cleaves preferentially the methionyl bonds in the Fc portion of IgG, and that the major fragment obtained, denoted F(ab'')(2), has still the combining properties of a divalent antibody. The possible therapeutic uses of F(ab'')(2) are discussed. (+info)
Specificity and sensitivity of the streptozyme test for the detection of streptococcal antibodies.
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A comparison between the results of the streptozyme hemagglutination test and serological titers for anti-streptolysin O (ASO), anti-hyaluronidase (AH), anti-deoxyribonuclease B (ADN-B), and anti-nicotinamide adenine dinucleotidase (ANAD) was made in two groups of human sera. In one group, serological titers for all the four antibodies were lower than the threshold of sensitization reported by the producing firm. In the second group, the titer of at least one of the four antibodies was equal to or higher than the threshold. False-positive and false-negative reactions occur with those sera when one or more antibody titer is at or near the threshold of the test as described by the manufacturer. The test was positive for all sera where either the ASO was greater than 166 or the ANAD was greater than 270, and for 98% of the sera with ADN-B greater than 360. It is, therefore, concluded that the streptozyme test can be used as an adjunct to the clinical diagnosis of streptococcal infections and their nonsuppurative sequelae. It is less useful to assess the levels of antibodies in sera from general population surveys. For such sera, the relative specificity and sensitivity of the test might yield misleading results. Until more experience is gained with the test, caution should be used in its application to infant and older adult age groups, where significant streptococcal antibody titers are frequently near the threshold of the test. (+info)
Acute rheumatic fever.
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While rheumatic fever is relatively uncommon except where there are poor and crowded living conditions, sporadic acute attacks continue to occur in a family or pediatric medical practice. The physician's role in management of the sore throat in the diagnosis of suspected cases of rheumatic fever and in follow-up for continued prophylaxis is discussed. The frequency of admissions and presenting features of 159 patients with acute rheumatic fever is reviewed. Continued surveillance is required if we are to achieve a further reduction in attack rate and complications. (+info)
Cellular reactivity studies to streptococcal antigens. Migration inhibition studies in patients with streptococcal infections and rheumatic fever.
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The question of whether hypersensitivity to streptococcal antigens plays a role in the pathogenesis of the nonsuppurative sequelae of streptococcal infections remains at present unclear. As a first step in the approach to this question, the degree of cellular reactivity of peripheral blood leucocytes to streptococcal antigens was investigated in a number of rheumatic fever patients, patients with uncomplicated streptococcal infections, as well as normal healthy subjects. Using the in vitro technique for the inhibition of capillary migration of peripheral blood leucocytes as an index of the degree of sensitivity to streptococcal antigens, the results indicate that patients with acute rheumatic fever exhibit an exaggerated cellular reactivity to these antigens and in particular to streptococcal cell membrane antigens. This abnormal response to streptococcal membrane antigens appears to persist in rheumatic subjects for at least 5 yr after the initial attack of rheumatic fever. Only Group A streptococcal membrane antigens elicited this unusual response in rheumatic subjects, since the cellular reactivity to Group C and D streptococcal membranes was the same in all groups. Patients with evidence of valvular disease exhibited the same degree of cellular reactivity to these antigens as did patients without clinical evidence of rheumatic heart disease. The nature of the antigens responsible for the observed cellular response remains unknown. Enzymatic treatment of streptococcal cell walls and membranes designed to remove type-specific M proteins did not alter the observed cellular reactivity to the streptococcal antigens. The finding that an abnormal cellular response to certain streptococcal antigens is present only in rheumatic patients suggests that cell-mediated factors may play an important role in the disease process. (+info)
An outbreak of streptococcal skin sepsis in a closed community.
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An outbreak of skin sepsis due to beta-haemolytic streptococcus group A M33, T3/13/B3264 occurred in a closed community. Staphylococcus aureus was also present in many of the lesions, but different strains were recognizable by phage typing. Environmental contamination was found. The outbreak was controlled by isolating infected boys and decontaminating the environment. Various aspects of the epidemiology and the pathogenesis of streptococcal infections are discussed. (+info)