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Biomedical subjects

K Lind

Publications and source records attributed to K Lind.

At least 19 recordsLinked to original sources

Enzyme immunoassay for detection of immunoglobulin M (IgM) and IgG antibodies to Mycoplasma pneumoniae.

An enzyme immunoassay (EIA) for detection of immunoglobulin M (IgM) and IgG antibodies to Mycoplasma pneumoniae was developed. The EIA was evaluated on the basis of results in the M. pneumoniae complement fixation (MPCF) test and the cold agglutinin test. Serum samples from 430 patients with respiratory infections of known or unknown etiology, from 91 healthy children and adults and from 20 patients with rheumatoid factor, were investigated. By the criteria chosen for positive diagnostic EIA values, we found that the combined measurement of specific IgM and IgG gave a specificity of 99.7% and a sensitivity of 97.8%. If only IgM antibodies were measured, the specificity was 100% and the sensitivity was 88%. For IgG alone the specificity was 99.7%, but the sensitivity was only 46% because of the high EIA cutoff value chosen for IgG. We found no false positives among serum samples from patients with non-M. pneumoniae respiratory infection of known etiology, and there were no false IgM positives due to rheumatoid factor. In some cases the IgM EIA results became positive earlier in the course of illness than the MPCF titer. While children and teenagers responded predominantly with IgM antibodies, patients older than 40 years often had an IgG response only (56% of cases), probably because of reinfection. We conclude that this EIA is a good alternative to the combined MPCF and cold agglutinin tests in the diagnosis of M. pneumoniae infection.

Adolescent

Ten and a half years seroepidemiology of Mycoplasma pneumoniae infection in Denmark.

The study was based on a computerized card index of 9161 patients who had at least one positive blood specimen in the Mycoplasma pneumoniae complement fixation test. A total of 12,562 specimens from these patients had been sent to Statens Seruminstitut from hospitals and general practitioners during a 10.5-year period. The period encompassed a previously described endemic period in a 30-year study of the epidemiological pattern of M. pneumoniae infection in Denmark. The serological data presented support the hypothesis advanced here that a more than sixfold increase of children in day care might have contributed to a change in the epidemiological pattern. The correlation between age and level of specific antibodies, as well as persistence of seropositivity, were also investigated.

Adolescent

Polymerase chain reaction for detection of Mycoplasma genitalium in clinical samples.

We have used the polymerase chain reaction to detect Mycoplasma genitalium in artificially seeded human throat swab samples as well as in clinical material. On the basis of the published nucleotide sequence of the M. genitalium 140-kDa adhesin gene, primers were chosen to produce an amplified fragment of 281 bp. Five different previously isolated strains, including the type strain of M. genitalium, could all be detected by the polymerase chain reaction, and DNAs from other mycoplasmal and bacterial species yielded negative results. The detection limits were estimated to be approximately 50 organisms by inspection of ethidium bromide-stained agarose gels and 4 organisms when a biotinylated oligonucleotide probe was used in filter hybridization. The amplified DNA fragments were subjected to restriction enzyme analysis. DNAs from the five different isolates all possessed EcoRI, SspI, AluI, Sau3AI, and DdeI restriction sites, as predicted from the published sequence. A total of 150 urogenital swabs collected from 100 patients for culturing of Chlamydia trachomatis were tested for the presence of M. genitalium DNA. Ten samples from eight patients were found positive. The amplified DNA fragments from all of our clinical samples possessed the AluI, Sau3AI, and DdeI restriction sites, but three samples from two patients did not contain the SspI site and none of the samples contained the EcoRI site.

Base Sequence

Covalently linked peptides for enzyme-linked immunosorbent assay.

A general method is described, by which synthetic peptides are covalently linked via their carboxyl group to microtiter plates (CovaLink) for enzyme-linked immunosorbent assay (ELISA). Plates were prepared by this method with an angiotensin II peptide and with an HIV-2 peptide and attachment detected by rabbit anti-angiotensin serum and with a positive serum from an HIV-2-infected patient, respectively, using the common ELISA procedure in the last steps. The method is simple to perform, it constitutes an alternative to the common ELISA method, and eliminates the risk of inadvertent loss of peptide during the procedure. The method is highly reproducible and has a high sensitivity. It may be used for either antigen or antibody detection.

Angiotensin II

Evaluation of a commercial enzyme immunoassay for detection of Mycoplasma pneumoniae specific immunoglobulin G antibodies.

A commercial enzyme immunoassay (Platelia Mycoplasma, Diagnostics Pasteur) for the diagnosis of Mycoplasma pneumoniae [corrected] infections was evaluated and found not to be suitable for the purpose. More than 80% of healthy persons and patients with non-Mycoplasma pneumoniae respiratory infection, all with a negative Mycoplasma pneumoniae complement fixation test, had a positive EIA. Paired sera did not show the positive correlation between a rise in complement fixation titre and the EIA ratio reported by the manufacturer.

Antibodies, Bacterial

Inhibitory effect of mycoplasma-released arginase. Activity in mixed-lymphocyte and tumour cell cultures.

Non-fermenting mycoplasma species deplete culture media for arginine through arginase activity linked to their arginine deiminase pathway, resulting in proliferation arrest and cell death in mycoplasma-contaminated cell cultures. The presence of only 2-3 Mycoplasma (M.) arginini-contaminated T cells in a one-way allogeneic mixed-lymphocyte culture (MLC) significantly inhibits development of cytotoxic T-cell activity. Likewise, strong degrees of inhibition are observed after addition of nanogram doses of M. arginini extracts (MAE) to MLC or cell proliferation cultures. M. arginini-induced cell inhibition can be reversed by addition of excess arginine to the culture medium. Antisera raised against non-fermenting, but not against fermenting, mycoplasma species block the inhibitory effect of MAE. SDS-PAGE separation of MAE disclosed a broad band at 60 kDa which contained arginase activity when assayed in MLC and cell proliferation culture. SDS-PAGE followed by western blotting and reaction with antisera raised against non-fermenting mycoplasma species demonstrated a band at 43 kDa common for these micro-organisms.

Animals

Detection of Mycoplasma pneumoniae in simulated clinical samples by polymerase chain reaction. Brief report.

Polymerase chain reaction (PCR) was used to detect Mycoplasma (M) pneumoniae DNA in simulated clinical samples. Throat swabs were mixed with known amounts of broth-grown M. pneumoniae cells. An estimated detection limit of less than 40 colony forming units (cfu) was obtained without the need for time-consuming hybridization. The PCR is completed in one day and may be useful for the early detection of M. pneumoniae in clinical samples.

DNA, Bacterial

Changes in the epidemiological pattern of Mycoplasma pneumoniae infections in Denmark. A 30 years survey.

A seroepidemiological survey has shown a remarkable shift in the previously reported regular cyclic pattern of Mycoplasma pneumoniae epidemics which culminated every 4.5 years during the period 1958-74. The last of four regular epidemics occurred in 1972. It was followed by 'premature' epidemics in 1975 and 1977/8 which inaugurated a change from an epidemic to an endemic pattern of the infection in Denmark. Over the following 9 years (1978-86) there has been an irregular but significant decrease in the annual number of seropositive samples with the usual high incidence during winter seasons. This endemic period terminated in the fourth trimester of 1987 with the development of a new epidemic. The hypothesis is advanced that a sixfold increase of children in day care may have influenced the change from an epidemic to an endemic situation which after 9 years led to a new epidemic of M. pneumoniae infection.

Agglutination Tests

Autoantibodies to the mitotic spindle apparatus in Mycoplasma pneumoniae disease.

Antibodies to the mitotic spindle apparatus (MS) have been detected in only a very few patient sera studied for antinuclear antibodies by routine screening (G. A. McCarty, D. W. Velencia, and M. J. Fritzler, J. Rheumatol. 11:213-218, 1984). We found anti-MS antibodies to be quite common in sera from patients with Mycoplasma pneumoniae, especially in those who developed cold agglutinins (71%). Absorption experiments indicated that the formation of anti-MS antibodies is not triggered by epitopes on the M. pneumoniae surface. These antibodies were distinct from cold agglutinins, antibrain antibodies, and smooth-muscle antibodies. All patients previously reported to harbor anti-MS had clinical features compatible with a diagnosis of systemic lupus erythematosus, rheumatoid arthritis, or an evolving connective-tissue disorder. Such systemic disorders might develop in a small proportion of patients who have had M. pneumoniae illness.

Autoantibodies

A new in-built device for one-point stepless prosthetic alignment.

The authors have developed a new in-built device for alignment of below-knee prostheses. The device allows one-point, stepless adjustment of angle and slide, independently of each other and also after completed prosthetic manufacture. Principally, the device consists of a half-sphere for angle adjustment and a plate for both slide adjustment and socket application. If the socket has to be exchanged, the whole device can be re-used, apart from the plate, which forms part of the socket bottom. The device is light, compact, cosmetically easy to cover and cheap. The design incorporates a combination of the most important facilities for alignment as well as for exchange of socket, and by its simplicity seems to offer major advantages over other designs.

Artificial Limbs

Seroepidemiological study of Legionella infection in Denmark. A 28-month retrospective survey.

An indirect immunofluorescence (IF) test for Legionella antibodies has been used since 1978 at Statens Seruminstitut, Copenhagen. An increasing annual number of blood specimens from all parts of the country has been tested by IF and the number of Legionella antigens in the test was increased from 4 over 10 to 13, resulting in an ever growing number of seropositive patients over the years. We investigated the occurrence of serologically diagnosed Legionella infections from November 1982 through February 1985, a period of 28 months during which the same 13 Legionella antigens were applied in the IF test. We used CDC's criteria for the serological diagnosis of a current Legionella infection: a greater than or equal to 4-fold rise in antibody titre to greater than or equal to 128 in the IF test. In a test of more than 5,000 blood specimens from 3,374 patients, 69 were found to have diagnostic titre rises. When analysed according to serological reactions with three groups of antigens, seroconversion to a L. pneumophila antigen was found to be more frequent in patients 30-59 years old than seroconversion to a non-L. pneumophila Legionella antigen, while in the age group 60-69 this relation was reversed. Thirteen of the 69 patients had acquired their infection abroad. Twelve of these were below the age of 60, and they had all seroconverted to a L. pneumophila antigen. Clinical data were in accordance with the assumption that Legionella may have been the aetiological agent of the disease in our patients selected by serological criteria.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

The E. coli immunosorbent as used in serodiagnosis of Legionella infections studied by crossed immunoelectrophoresis.

In this study we investigated an immunosorbent, E. coli blocking fluid (BF), proposed for use in the Legionella Indirect Fluorescent Antibody Test (IFA). With crossed immunoelectrophoresis (CIE) of clinically relevant Legionella species, only one heat-stable antigen (no. 1) cross-reacted with the BF preparation. Patients' sera with elevated Legionella IFA titres did not react with this antigen in CIE. Out of 23 IFA positive patients' sera, six had titres lowered significantly to negative, when BF was applied as serum diluent for the titration (IFA BF negative sera). All six sera were negative in the micro agglutination test (MA). None of the IFA BF negative sera contained any Legionella precipitins in CIE, whereas nine out of the remaining 17 IFA BF positive sera unchanged by BF contained one or more precipitins. CIE results could not explain the effect of BF in Legionella IFA, and further studies are needed to sufficiently define the use of immunosorbents in diagnostic Legionella serology.

Antibodies, Bacterial

Significance of antibodies to Mycoplasma genitalium in salpingitis.

Indirect haemagglutination and indirect immunofluorescence tests of sera from 95 patients with acute salpingitis failed to confirm the report of other investigators regarding serological evidence implicating Mycoplasma genitalium in pelvic inflammatory disease. The pathological role of Mycoplasma genitalium in salpingitis, non-gonococcal urethritis, and other diseases has not been proven.

Acute Disease

Aortic valve endocarditis associated with Legionella infection after Mycoplasma pneumonia.

A 38 year old woman with diabetes mellitus and bronchial asthma was admitted to hospital with pneumonia caused by Mycoplasma pneumoniae; she recovered promptly on erythromycin treatment. Six weeks later she presented with aortic valve endocarditis without concurrent lung disease. A concurrent increase in titres of antibody to Legionella bozemanii, L longbeachae, and L jordanis indicated a Legionella infection. Legionella infection should be considered, even in the absence of pneumonia, in cases of endocarditis where no other cause can be detected.

Adult

Cloning of Mycoplasma pneumoniae DNA and expression of P1-epitopes in Escherichia coli.

A genomic library of Mycoplasma pneumoniae was constructed by cloning partial Sau3A-digested genomic DNA into the expression plasmids pEX1 to pEX3. The recombinant clones were screened for production of M. pneumoniae P1-antigen by an in situ colony enzyme-linked immunosorbent assay (ELISA) blot method with a monospecific rabbit antiserum raised against the surface protein P1. The length of the translated P1-sequence and the size of the inserted DNA were determined. By comparison it was shown that six clones contained DNA fragments coding for an internal part of the P1-protein and eight clones code for the C-terminal part of terminated P1-protein. In reactions against sera from patients suffering from M. pneumoniae infection and sera from healthy persons, one of the internal clones and five of the C-terminal clones reacted with one or two of the patient sera, but only one clone reacted with all patient sera.

Antibodies, Bacterial