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Biomedical subjects

H D Mierau

Publications and source records attributed to H D Mierau.

At least 19 recordsLinked to original sources
PubMed1989

[Habit patterns in the use of the manual toothbrush. 1].

It is the goal of this study to quantitatively assess the habit patterns of toothbrushing. In the course of nine sessions such variables as force, duration, technique (scrubbing, rotating, or sweeping) as well as the sequence of brush positions and the number of changes of brushing sites were determined in 85 men and women, who were neither motivated nor instructed to maintain oral hygiene. The "force of habit" was an unexpectedly dominant factor, the least variations being observed in the brushing technique. On the other hand, a comparison of the degrees of habit of patients with and without acute or chronic brush-induced lesions (gingival recession, Stillman's clefts, wedge-shaped defects) revealed that patients with gingival recessions had the highest degree of habit. Consequences of clinical relevance are pointed out.

Adult↗
PubMed1981

Lysosomal elastase: effect on mechanical and biochemical properties of normal cartilage, inhibition by polysulfonated glycosaminoglycan, and binding to chondrocytes.

Rheumatic joint destruction usually starts with the destabilisation of cartilage. Lysosomal elastase is a candidate effector of this process, since this enzyme is found at the site of cartilage erosion by rheumatoid synovial tissue. In order to prove this hypothesis we assessed the mechanical stability of cartilage during treatment by this enzyme in vitro. An indentation apparatus was used for this purpose and biochemical as well as microscopic techniques were used to supplement the results thus obtained. Our findings show that elastase irreversibly impairs the stability of cartilage by lysis of matrix proteoglycans without the help of additive enzymes. Collagen fragmentation played no significant role during elastase-induced destabilisation, while specific collagenase attacked the collagen network within the matrix only subsequent to the removal of proteoglycans. These findings suggest that elastase is a leading enzyme during proteolytic cartilage degradation. In addition polysulfonated glycosaminoglycan was found to reduce the mechanical effect of elastase on normal cartilage. It is therefore concluded that local inhibition of elastase promises therapeutic benefit during rheumatic cartilage degradation. Upon treatment of cartilage with elastase we observed this enzyme not only within the matrix under destruction but also bound to chondrocytes. These findings support the hypothesis that elastase plays a role on the matrix not only by direct degradation, but also by an indirect effect mediated through living chondrocytes.

Adolescent↗
PubMed1979

[Reproducibility of plaque formation in the dento-gingival region. 4].

The reproducibility of plaque was quantitatively determined in three twelve-day examination periods. The periodontium of the subjects was healthy; tendencies for plaque formation were extreme or slight. Plaque formation was studied on teeth 33 to 43; the vestibular surface was divided into 1,600 areas, according to topographic factors. The absence and appearance of plaque three times tends to indicate a causal event in that particular area. The results were as follows:1) The reproducibility of plaque formation with "slight" plaque patterns is no lower than with "severe" plaque patterns. 2) The dominating influence of the microrelief (surface roughness) compared with the macrorelief (form of the tooth, tooth position) and other factors holds true for subjects with a tendency for severe and slight plaque formation. 3) Plaque may be formed by several different factors; these factors will affect various topographic zones of the tooth surface differently. Many other differences were reported in subjects with severe or weak plaque formation. 4) Terms of preventive dentistry, the evaluation of surface roughness of the teeth, particularly with adolescents, is necessary in each dental practice.

Adolescent↗