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J H Larsen

Publications and source records attributed to J H Larsen.

At least 37 records · Page 2Linked to original sources
PubMed1986

Comparison of a fluorescent monoclonal antibody assay and a tissue culture assay for routine detection of infections caused by Chlamydia trachomatis.

The applicability of a commercial direct immunofluorescent monoclonal antibody assay for detection of Chlamydia trachomatis elementary bodies was studied on endocervical smears from 506 women attending a venereal disease clinic. The aim of this prospective examination was to simulate a daily routine. The results were compared to those of a well-functioning tissue culture assay. The overall positivity was 22.7%. Based on a positivity criterion of greater than or equal to 1 elementary body in the fluorescent antibody assay, the two assays agreed in 84.8% of the cases. In 50 specimens the antibody assay was positive and the culture assay negative, whereas in 23 the culture assay was positive and the antibody assay negative. The positive predictive value was 63.8%. Most of the discrepancies were found in specimens containing few elementary bodies or inclusions. Based on a criterion of greater than or equal to 10 elementary bodies, the positive predictive value was 70.9%, but the sensitivity fell to 67.5%.

Antibodies, Monoclonal↗
PubMed1985

The determination of specific IgA-antibodies to Yersinia enterocolitica and their role in enteric infections and their complications.

Specific serum IgA-antibodies, mainly produced in the lymphoid tissue of the gastrointestinal tract (GALT) might exhibit some special characteristics deviating from IgM- and IgG-antibodies: they do not agglutinate nor fix complement. They cannot be determined by usual routine antibody techniques; indirect methods must be used. An antiglobulin-assay was used in an extensive investigation over a two-year period on sera from 8,445 patients to determine IgA-antibodies specific to Yersinia enterocolitica, serotype 3. Y. enterocolitica agglutinins were found in 965 patients, 508 of them with significant titres of greater than or equal to 80. 347 of the 2,111 patients with low titres (10 to 40) had a significantly elevated amount of IgA antibodies. The diagnoses of the IgA-positive patients fell into three groups: acute infections, acute reactive complicatory inflammations, mainly arthritis, chronic inflammatory connective tissue diseases. The IgA-antibody pattern was: In early samples from patients with acute enteric infections they might be the only antibodies present following, largely, during the course of the disease the agglutinating IgM and IgG antibodies, except in patients with long-lasting or chronic complications where IgA antibodies were elevated. It is concluded that determination of specific antibodies of IgA class in cases of Y. enterocolitica infections is an important diagnostic test and, moreover, of prognostic value in the evaluation of chronicity.

Adolescent↗
PubMed1982

The prevalence of antibodies to hemolytic Streptococci and Yersinia enterocolitica in Danish school children and among hospitalized patients.

Serological investigations in infections caused by hemolytic streptococci and by Yersinia enterocolitica (Y. ent.) can be diagnostically decisive. Here are presented the results of 2 extensive serologic investigations of a population of school children (n = 929) and of hospitalized patients (n = 2121). It is shown that only very high titers of streptococcal antibodies were of diagnostic value in single samples as most other titers had the same distribution and frequency in the healthy population. Titers of antibodies to Y. ent. were elevated 5 times more often in the hospital patients than in the healthy population. Antibodies to Y. ent. were approximately at the same level in all age groups in contrast to the streptococcal antibodies, which decreased with age. In about 4% of the 2121 patients investigated elevated antibody titers to both bacteria were found simultaneously. The differential diagnosis may be difficult in such cases especially if they exhibit symptoms of rheumatic fever.

Adolescent↗
PubMed1981

Microfilaments interacting with heavy meromyosin and deoxyribonuclease I in cells of the ovarian follicle of a lizard.

Two types of filaments (microfilaments 4--6 nm in diameter, and intermediate filaments 7--10 nm in diameter) are common in the surface epithelial cells and theca fibroblasts of vitellogenic ovarian follicles of the lizard Anolis carolinensis. Heavy meromyosin (HMM), which forms complexes with actin filaments, interacts only with the microfilaments of theca fibroblasts. After myosin extraction of follicles no filaments disappeared, but when this treatment was followed by incubation with deoxyribonuclease I (DNA-ase I), which depolymerizes F-actin to G-actin, microfilaments disappeared from the theca fibroblasts. It is concluded that microfilaments in theca fibroblasts are actin-like and may contract to provide the mechanism of expulsion for the oocyte during ovulation. The intermediate filaments of the surface epithelial cells and theca fibroblasts may serve as a skeletal system for the large (up to 8 mm in diameter) vitellogenic follicle.

Animals↗
PubMed1981

Prevalence of raised Yersinia enterocolitica antibody titre in unselected, adult populations in Denmark during 12 years.

Yersinia enterocolitica biotype 4, serotype 0:3 is by far the most common human pathogenic Yersinia enterocolitica subtype in Scandinavia. It is extraordinarily immunologically specific, and an elevated antibody titre greater than or equal 80-160 is known to indicate acute infection. This titre was measured in five population surveys conducted in 1967-78, including 3278 examined adult men and women. The prevalence of titre elevation greater than or equal to was 1.0% in 1967. In 1978 it was significantly higher, 7.7%, and also the individual course of the titre in a ten-year longitudinal survey showed a significant increase in this prevalence, indicating an increasing incidence of infection. Significant sex and age differences were seen, women and younger subjects being more frequently affected than men and older subjects. The prevalence of elevated titre showed a seasonal variation with a maximum in the spring and autumn.

Adolescent↗
PubMed1981

Glomerulonephritis in infections with Yersinia enterocolitica O-serotype 3. II. The incidence and immunological features of Yersinia infection in a consecutive glomerulonephritis population.

In a consecutive series of 38 patients with acute glomerulonephritis (GN), 17 showed serological or immunological signs of current or previous yersiniosis. None of these 17 patients had raised antistreptolysin-o titres. Only half of these patients had had clinical symptoms of Yersinia infection. Light microscopic examination revealed that 12 of the 17 patients had proliferative and 4 epimembranous GN. In 8 out of 14 biopsy specimens, Yersinia antigen could be demonstrated by immunoglobulins and complement. Immunofluorescence microscopy examination of all biopsy specimens containing sufficient tissue for a valid analysis showed deposits of complement and immunoglobulin G, most specimens also immunoglobulins A and M. It is considered highly likely that Y. ent. O:3 may be, and frequently is, an etiological factor for development of acute GN. It would be advisable not only to investigate all patients with acute GN for streptococcal infections, but also to carry out serological and bacteriological tests for Y. eng. O:3 infection and to institute an active therapeutic approach to acute infections caused by this bacterium.

Acute Disease↗
PubMed1980

Yersinia enterocolitica infections and rheumatic diseases.

Yersinia enterocolitica (Y. ent.) infections are rather frequently complicated by acute reactive inflammation in the connective tissue, especially in the joints. At this stage of the disease the specific diagnosis can be obtained either by bacterial isolation and identification from the feces and/or mesenterial lymph nodes, or by serological methods. Serodiagnostics are frequently the only method during the complication phase, since the bacteria have often disappeared from the feces by this stage of the disease. Specific Y. ent. serodiagnostics are benefitted by the fact that no antisera cross-react with the serotype 3 thermostable O-antigen. A titre of greater than or equal to 80 is therefore highly indicative of a recent or current Y. ent. infection. In the absence of other known arthritogenic agents the Y. ent. antibodies are highly indicative of the Y. ent. etiology of a current disease. The Y. ent. complications affect most inflammatory reactive diseases, acute as well as chronic. In an area in which Y. ent. infections are endemic, Y. ent. is the most frequent cause of acute and chronic arthritis. The present results indicate that not all cases of acute Y. ent. arthritis remit, but some persist, usually with an intermittent course, and develop into rheumatoid arthritis or allied conditions. This suggests a common pathogenic mechanism in most inflammatory rheumatic diseases. It is proposed that the time has come for a classification of these diseases based on their etiology, in order to replace the present symptom-based treatment with a causal one, and to institute prophylactic measures. The pathology is not exclusive to Y. ent., but can presumably also be brought about by other bacteria, such as gonococci, meningococci, salmonellae, shigellae, and brucellae, possibly by their content of lipopolysaccharide.

Adult↗
PubMed1979

Oocyte-follicle cell relationships in a starfish.

The follicle cells which surround the oocytes of starfish are known to both release the hormone 1-methyladenine and to respond to it by an active movement which forms a component of the spawning response to the hormone. In Patiria miniata these flagellated cells are located peripheral to the oocyte and have long cytoplasmic processes which penetrate the vitelline layer to the egg surface to form an adhering zonule-like junction. Within the follicle cell cytoplasm are located elongate filamentous bands which appear to represent a component of the contractile mechanism that mediates follicle cell response to 1-methyladenine. These bands do not resemble the filaments of vertebrate smooth muscle cells (quantity, distribution and size of filaments; lack of dense bodies in the filament mass), nor the contractile units of the superficial epithelium of lower vertebrate follicles.

Animals↗
PubMed1979

Yersinia enterocolitica infection and sarcoidosis. A report of seven cases.

Sarcoidosis of recent onset was diagnosed during a Yersinia enterocolitica infection in seven patients at the Copenhagen County Hospitals during a 3 1/2 year period. In all cases the diagnosis was made from clinical symptoms and confirmed by chest X-ray and biopsy. In five of the patients a fourfold rise or decrease was measured in the antibody titre against Yersinia enterocolitica, serotype 3, confirming an acute infection. In another two patients this titre remained significantly elevated greater than or equal to 80, indicating chronic infection. Five patients experienced joint symptoms and four erythema nodosum, symptoms common to both yersiniosis and sarcoidosis. A follow-up examination 14 to 41 months after the debut of sarcoidosis showed total remission (including chest X-ray and respiratory function) in five of the seven patients. Recent research has shown that Yersinia enterocolitica following the early stage of the infection causes granulomatous lesions in lymph follicles, and this aetiology should thus be considered as a differential diagnosis to sarcoidosis.

Adult↗