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Biomedical subjects

P L Meenhorst

Publications and source records attributed to P L Meenhorst.

At least 91 records · Page 5Linked to original sources
PubMed1989

Polyarticular Salmonella bacterial arthritis in a patient with systemic lupus erythematosus.

Patients with systemic lupus erythematosus (SLE) are at increased risk for infections. Insufficiency of the reticuloendothelial system caused either by immunosuppressive therapy or inadequate opsonisation are mechanisms by which Salmonella infections in particular appear in these patients. Salmonella infections can provoke a polyarticular reactive arthritis while Salmonella bacterial arthritis usually is monarticular. We report on the seriousness of a Salmonella infection (enteritis complicated by polyarticular bacterial arthritis) in a patient with SLE.

Adult↗
PubMed1988

Characteristics of anti-Legionella antibodies in patients infected with Legionella pneumophila serogroups 1, 6, and 10.

Nosocomial infections with Legionella pneumophila serogroups 1 and 10 in the Leiden University Hospital and infections with L. pneumophila serogroup 6 in neighboring hospitals gave us an opportunity to study the development of opsonizing antibodies against L. pneumophila serogroups 1, 6, and 10 in the serum of 13 patients. Seven of these patients were infected with L. pneumophila serogroup 1, two were infected with serogroup 6, and four were infected with serogroup 10. The opsonic cross-reactivity of antibodies against these serogroups of L. pneumophila and complement involvement in opsonization were also investigated. Convalescent-phase sera from patients infected with L. pneumophila serogroup 1 or 6 were able to promote ingestion of these serogroups by polymorphonuclear leukocytes, whereas ingestion of L. pneumophila serogroup 10 was enhanced only in the presence of convalescent-phase sera from patients infected with this serogroup. Opsonization of L. pneumophila serogroups 1, 6, and 10 was complement dependent.

Antibodies, Bacterial↗
PubMed1987

The course of Legionella pneumonia in guinea pigs after inhalation of various quantities of L. pneumophila.

The course of legionella pneumonia in guinea pigs after infection with various quantities of virulent L. pneumophila serogroup 1 organisms by aerosol exposure was investigated. The clinical course, histopathological characteristics, manifestations in the lungs and clearance of the legionella organisms from the lungs and spleen were followed. Four groups were exposed to 4.3 X 10(4), 4.7 X 10(5), 5.0 X 10(6) and 1.0 X 10(8) aerosolized legionellae, respectively. The most striking clinical symptoms were fever and weight loss, which were found in 67-94% and 33-100% of the animals, depending on the dose of L. pneumophila organisms administered. Spontaneous death occurred only in animals receiving the highest dose and always within 10 days. All animals exhibited exponential growth of legionella organisms in the lungs. Maximal growth occurred 5 to 7 days after exposure and varied from 9.3 X 10(7) to 7.4 X 10(8) organisms/both lungs. Twenty-two days after exposure, legionellae could still be cultured from lung tissue. Between 2 and 7 days after exposure, the spleen cultures were positive for legionellae in 41% of the animals receiving the lowest dose and in 83% of all other animals; legionellae could no longer be cultured from spleen tissue after day 7. Depending on the dose, peripherally localized areas of bronchopneumonia increased in size with time, tending to become confluent lobar pneumonia. The microscopic changes were not related to the number of inhaled organisms. In the cellular infiltrate, PMN predominated until day 7 and macrophages thereafter. Seroconversion was found in all animals that survived greater than 7 days. The present animal model closely mimics the course of events in human legionella pneumonia, thus enabling us to further study the factors involved in host resistance against legionella as well as the efficacy of various antimicrobial agents in normal and immunosuppressed animals.

Animals↗
PubMed1986

Effect of rubbers and their constituents on proliferation of Legionella pneumophila in naturally contaminated hot water.

The proliferation of Legionella pneumophila serogroups 1, 9, and 10 in naturally contaminated hot potable water was measured after the addition of various rubbers and their constituents. When compared with controls 9/14 rubbers and 15/30 constituents shortened lag time for growth of L pneumophila at 37 degrees C and, produced a 10-100 000 fold increase in the number of L pneumophila organisms. In most experiments this increase was due mainly to the growth of L pneumophila serogroup 10, which predominated in all fresh water samples (47-53 degrees C); in others a shift in predominance from serogroup 10 to serogroup 1 occurred. Rubbers containing thiuram did not enhance the growth of L pneumophila, while the addition of thiuram alone inhibited growth. Therefore thiuram-containing rubbers should be used in water systems.

Equipment Contamination↗
PubMed1985

Water-related nosocomial pneumonia caused by Legionella pneumophila serogroups 1 and 10.

Between August 1978 and November 1983, 21 cases of pneumonia caused by Legionella pneumophila occurred in the Leiden University Hospital, mainly among immunocompromised patients. A new serogroup of L. pneumophila, designated serogroup 10 (prototype strain Leiden 1), was isolated from bronchial secretions of four patients, and five patients had serological evidence of infection with this organism. Nine patients had a culture-confirmed infection with L. pneumophila serogroup 1. L. pneumophila serogroups 1 and 10 were also isolated from the hot potable water supply in the building to which 19 of the 21 patients had been admitted. The isolates of L. pneumophila serogroup 1 from patients and the hot potable water were identical in studies with monoclonal antibodies and had the same plasmid profiles. These findings provide further evidence that in our hospital potable water contaminated with L. pneumophila is a source of infection, mainly in immunocompromised patients.

Adult↗
PubMed1985

Cross-reactive urinary antigens among patients infected with Legionella pneumophila serogroups 1 and 4 and the Leiden 1 strain.

A solid-phase radioimmunoassay was developed to detect antigens of Legionella pneumophila serogroup 4. The assay detected antigen in urine from four of seven patients with pneumonia caused by L. pneumophila serogroup 4, two of two patients with L. pneumophila Leiden 1 strain (proposed new serogroup), and 26 of 55 patients with L. pneumophila serogroup 1 (proven by culture or direct fluorescent-antibody assay). The antigen of two patients with serogroup 4, one with Leiden 1 strain, and 49 with serogroup 1 infections could be detected in a previously described assay for antigens of L. pneumophila serogroup 1. Serogroup specificity of the assays could be demonstrated if serial dilutions of urine were tested. None of 347 urine specimens used as controls were positive in the radioimmunoassay. We conclude that antigens are excreted in the urine of at least some patients with Legionnaires' disease caused by serogroup 4 and Leiden 1 strain. The urinary antigens in patients with serogroup 4 and Leiden 1 strain infections, although different from those in patients with serogroup 1 infections, serologically contain cross-reactive components.

Antigens, Bacterial↗
PubMed1984

Comparative clinical study on the absorption of orally administered amoxycillin and bacampicillin.

In nine consecutive hospitalized patients treated with either ampicillin or amoxycillin, studies on the pharmacokinetics of orally administered amoxycillin and bacampicillin gave a mean absorption of 73% (+/- 15%) of the dose for amoxycillin and 65% (+/- 17%) for bacampicillin. An analysis of variance showed that the difference between the two drugs has only borderline significance (P less than 0.10). These mean values are lower than those reported in the literature for healthy volunteers, and the variation between patients is also larger. The mean absorption rates found for the two drugs did not differ from those found in healthy volunteers, amoxycillin being absorbed significantly more slowly than bacampicillin (P less than 0.02), but there were also large differences between patients.

Administration, Oral↗
PubMed1983

Legionella pneumonia in guinea pigs exposed to aerosols of concentrated potable water from a hospital with nosocomial Legionnaires' disease.

An investigation of an outbreak of nosocomial legionella pneumonia revealed that the potable water of the hospital was contaminated with a distinctive strain of Legionella pneumophila (designated the Le-1 strain), which was by culture and serology linked with human illness. To examine the possible role of this water in this outbreak, eight healthy guinea pigs were exposed to an aerosol of concentrated potable water. Seven animals developed pneumonia due to the Le-1 strain of L. pneumophila. In one of these guinea pigs, the Le-1 strain was also isolated from the blood and spleen. These results provide support to the theory that exposure of humans to aerosols of potable water contaminated with L. pneumophila may cause legionella pneumonia.

Aerosols↗
PubMed1983

Detection of antibodies against Legionella pneumophila serogroups 1 to 6 and the Leiden-1 strain by micro ELISA and immunofluorescence assay.

One hundred and seventy-five human sera were tested for the presence of type-specific antibodies against L pneumophila serogroups 1 to 6 and the Leiden-1 strain by means of an enzyme linked immunosorbent assay (ELISA) and compared with the results obtained by the indirect immunofluorescence assay (IFA). A high correlation (correlation coefficient 0.92) between both methods was found. No consistent pattern of IgG, IgA and IgM classes of antibody titres against L pneumophila were found. In the sera of 15 of 17 patients with a proven L pneumophila pneumonia, IgM class antibodies against L pneumophila could be detected. A "polyvalent" ELISA was developed which permits rapid routine screening of human sera for antibodies against L pneumophila serogroups 1 to 6 and the Leiden-1 strain.

Antibodies, Bacterial↗
PubMed1983

The chest X-ray in Legionella Pneumonia (Legionnaires' disease).

The authors compared the radiological evolution and patterns of Legionella pneumophila pneumonia in 13 immunocompromised and 13 non-immunocompromised patients. Apart from the occurrence of cavitation and the longer time it took before consolidations cleared in immunocompromised patients no differences were found between the two groups of patients.

Adult↗
PubMed1983

Sporadic cases versus outbreak associated cases of Legionella pneumonia.

Sporadic cases and outbreaks of Legionella pneumonia are more commonly recognized; especially among hospitalized patients. Factors predisposing to L. pneumophila pneumonia and the clinical features of this type of pneumonia are similar for epidemic and sporadic cases. It is difficult to compare overall mortality figures of various epidemics and series of sporadic community-acquired cases of Legionella pneumonia, because the factors that determine the severity and outcome of Legionella pneumonia are poorly defined in most series.

Disease Outbreaks↗