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P Otte

Publications and source records attributed to P Otte.

30 records · Page 2Linked to original sources
PubMedDate not supplied

[Osteopenia, marrow atrophy and capillary circulation. Comparative studies of the human iliac crest and 1st lumbar vertebra].

Histological and histomorphometrical measurements were made on normal and on osteoporotic bone from the first lumbar vertebra and the iliac crest of 15 cases. A decrease in cancellous bone was found in both. This was accompanied by a reduction in haematopoietic marrow and a corresponding increase in fat cells. In addition, the numbers of arterial capillaries and sinuses per unit area were also reduced. There is a greater overall vascularization in the first lumbar vertebra than in the iliac crest, even though the amount of cancellous bone is normally less in the former. However, the arborization of the terminal vessels in the iliac crest is more extensive than that in the first lumbar vertebra. These observations provide support for the participation of a vascular component in the pathogenesis of osteoporosis.

Adipose Tissue↗
PubMedDate not supplied

Basic cell metabolism of articular cartilage. Manometric studies.

Basic metabolism generates energy by the anaerobic or aerobic metabolization of glucose. The articular cartilage obtains the substrate and oxygen from the synovial fluid. Their concentrations within the cartilage diminish with increasing proximity to the basal layer at the bone-cartilage boundary. The gradients depend upon the cell density and the consumption by the cells. The gradient of the partial oxygen pressure (PO2) could provide the conditions for the Pasteur effect, which, however, has not yet been clearly observed. Metabolic reactions of chondrocytes to positive or negative glucose gradient have not hitherto been examined, and are the object of the present study. The oxygen consumption (QO2) in the articular cartilage of pig femoral heads was measured manometrically (Warburg technique) in the absence of glucose and in its presence in concentrations of 1.25 to 10.0 mM. There was a close correlation between the QO2 and the concentration and consumption of glucose having the nature of a glucose-induced respiratory suppression (Crabtree effect). The consumption of glucose, which did not rise in proportion to its concentration, did not exceed 15.7 mumol/gdw/h. The maximum lactate production of 20 to 23 mumol/gdw/h was attained at 5 mM glucose and showed no further increase at higher substrate concentrations. This stoichiometric "lactate deficiency" means that the absorbed but not glycolyzed glucose is channeled into synthesizing and storage processes. In glucose-free incubation, despite aerobic conditions, lactate was utilized by the chondrocytes only at unphysiologically high concentrations greater than 10 mM. Potassium cyanide reduced the QO2 by only 80-90% as a sign of the activity of non-mitochondrial oxidases. With monoiodoacetate (MIA), respiration fell dramatically during the 4 h of substrate-free incubation. It can be concluded from the results that, under physiological conditions, the glucose level in the synovia reduces the consumption of oxygen in the well-glucose-supplied upper layer of the articular cartilage, thus allowing an oxidative compensation of the diminishing glycolysis in the basal zone. The Crabtree effect, which is demonstrated for the first time in chondrocytes, thus seems to have the role of an essential regulatory mechanism in the basic metabolism of the cartilage.

Animals↗
PubMedDate not supplied

[Aging phenomena and arthrosis].

The incidence of arthroses has a highly significant correlation with age. However, a clearly defined relationship from a causal basis does not yet exist. This association is not through the time-dependent accumulation derived from the mechanical "destruction-quantum" at a molecular level in the cartilage. Indicative for the transformation is progressive degeneration with considerations of disease values, norms, and biochemical parameters of the joint and associated indicators. We use the example of the knee joint to illustrate this point. The discrepancy over deficit in strength and regulatory mechanisms is also considered, as well as the passive chondroprotective shock-absorption of the subchondralia spongiosa, and, conversely, the apparent protective mechanism of osteoporosis preceding arthrosis. Epidemiologically, osteoporosis and arthroses have been proven incompatible; what remains to be elucidated is the well-known dichotomy in their courses of development.

Aged↗