Biomedical subjects

A van Loon

Publications and source records attributed to A van Loon.

5 recordsLinked to original sources

PubMed1992

The postpolio syndrome: no evidence for poliovirus persistence.

To investigate the possibility of poliovirus persistence in patients with the postpolio syndrome, we examined skeletal muscle biopsy specimens, cerebrospinal fluid specimens, and sera for the presence of poliovirus RNA by the polymerase chain reaction, and for IgM antibodies by a poliovirus type-specific IgM antibody-capture enzyme-linked immunosorbent assay. In none of these specimens was poliovirus RNA or a poliovirus type-specific IgM response detected. These results argue against the hypothesis that poliovirus persists in patients with the postpolio syndrome and plays a role in the pathogenesis of the postpolio syndrome.

Antibodies, Viral↗

PubMed1990

[Partial and total patellectomy as treatment of comminuted patella fracture].

When accurate reduction and stable fixation cannot be achieved in comminuted patellar fractures, degenerative changes in the patellofemoral joint can cause troublesome complaints. Our results show that partial or total patellectomy can produce a very good percentage of satisfactory results. In spite of several biomechanical studies that demonstrated the reduced efficiency of the quadriceps mechanism after partial and total excision of the patella, most patients achieved good or excellent results after a long follow-up period. All patients showed decreased isokinetic performance of the quadriceps muscle. There was no clear correlation between the clinical score and the data on isokinetic performance. Patellofemoral or femorotibial osteoarthritis and calcifications in the patellar ligament did not lead to an unsatisfactory clinical result.

Biomechanical Phenomena↗

PubMed1989

Some variables in the blue (red) phenomenon.

The relation between spontaneous color choices and ratings of the prototypicality, conspicuousness, and pleasantness of colors was studied in a sample of Dutch college students. Pleasantness, not prototypicality or conspicuousness, determined the four most frequent spontaneous choices--red, blue, green, and purple. Subjects considered blue the most pleasant of the 12 colors studied, which suggests a pleasantness explanation for the "blue phenomenon" found in some countries. The predominance of red as a spontaneous choice replicated the results of previous studies in the Netherlands. Red also was rated highest in prototypicality but was not rated higher by red choosers than by choosers of other colors, so that a simple prototypicality explanation was rejected. Further analysis showed that the predominance of red as the spontaneous choice of Dutch subjects can be explained by an interaction between prototypicality and pleasantness: Subjects tended to choose red when they rated it highly on both variables.

Adult↗

PubMed1987

An enzyme-immunoassay for antibodies against hepatitis B core antigen: characteristics and clinical validation.

An enzyme-immunoassay (EIA) for antibodies to hepatitis B core antigen (anti-HBc) was developed. The new test uses undiluted samples, incubated directly into an HBcAg coated well. Three alternative test procedures are possible. The stability of reagents was studied and a preclinical evaluation was performed intramurally. An assay correlation study was organised. We report the results of the external evaluation performed at 4 centres. A mean analytical sensitivity of 1.1, 1.2 and 0.36 PEI units/ml anti-HBc was found for procedure I (1 h/1 h/30 min), procedure II (30 min/30 min/30 min) and procedure III (16-20 h/1 h/30 min), respectively. In total, 5288 determinations on serum or plasma from various patients and healthy individuals were performed: 10% with procedure I, 52% with procedure II and 38% with procedure III. The qualitative (positive or negative) results were compared with those found with tests used routinely at the centres--47% with Corzyme (Abbott) and 53% with Corab (Abbott)--in a first screening. A final evaluation was made taking into account the repeatability of the results. Based on all results together, the agreement between the new EIA for anti-HBc and the routine tests was 97.6% at the first screening and increased to 99.0% after further evaluation.

Blood Donors↗

PubMed1979

[ELISA].

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Enzyme-Linked Immunosorbent Assay↗