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Biomedical subjects

K Abendroth

Publications and source records attributed to K Abendroth.

At least 19 recordsLinked to original sources
PubMed1992

Quantitative study of articular cartilage and subchondral bone remodeling in the knee joint of dogs after strenuous running training.

All tissues of the joint are affected in some way in osteoarthritis because the joint is an interactively functioning unit. Our goal was to investigate the combined responses of articular cartilage and subchondral bone to altered loading conditions to improve our understanding of the physiology of these two components and, ultimately, the pathophysiology of osteoarthritis. A group of 20 female beagle dogs were divided pairwise into runners (n = 10) and controls (n = 10). The running training on a treadmill started at the age of 15 weeks, and during the following 40 weeks the running distance was gradually increased to 40 km/day with a 15 degree uphill inclination. With this daily running distance the beagles ran another 15 weeks. The samples for histology were taken from 11 different locations of the knee joint. Subchondral bone and articular cartilage histomorphometry was carried out in three different regions of the specimens (central, middle, and peripheral regions) using an image-analyzing system and an eyepiece graticule. In all regions of the articular cartilage, both the uncalcified and calcified cartilage showed slightly increased thickness in the runner dogs. The change was more evident in the peripheral and the central areas. The thickness of the subchondral bone plate tended to be higher in runners, too. Bone histomorphometric parameters showed significant signs of increased remodeling. The most notable change was the enlargement of the bone formation surface. The most intense remodeling was usually observed either centrally or peripherally in the articular surface. The strongest increase in trabecular bone volume and thickness of the cartilage was recorded in the femoropatellar area.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Beta-2-microglobulin-derived amyloidosis: onset, distribution and clinical features in 13 hemodialysed patients.

Postmortem examinations were carried out in 13 patients (6 males, 7 females, age 58 +/- 9 years) who had been on regular hemodialysis treatment for 10-90 months using disposable regenerated cellulose membrane dialyzers. The prevalence of beta 2-microglobulin (beta 2m)-derived AB-amyloid deposits in different sites was determined. At autopsy, specimens were obtained from different joints, paravertebral tissue, intervertebral discs and from visceral organs. During life, routine laboratory parameters and radiographic studies had been carried out at 6-month intervals. Serum levels of beta 2m were elevated in all patients (57.5 +/- 13.4 mg/l). Synovial AB-amyloid deposits were shown in different joints of 4 patients, aged between 59 and 73 years, and dialysed for 10-90 months, respectively. All had been unremarkable by X-ray and asymptomatic. No amyloid could be detected in the intervertebral discs of 2 further patients suffering from destructive spondylarthropathy. In 11 of the 13 patients, extracellular beta 2m deposits were observed by immunohistochemistry in different tissues. The results document that (a) AB-amyloidosis may occur in elderly patients even when dialysed for less than 5 years; (b) most cases are completely asymptomatic; the appearance of symptoms must be dependent on additional factors, e.g., site of AB-amyloid deposition and intensity of inflammatory reaction, and (c) AB-amyloid is not the exclusive cause of destructive spondylarthropathy, as 2 typical cases were observed who were devoid of amyloid.

Amyloidosis↗
PubMed1991

Studies on psoriatic osteopathy.

To demonstrate an as yet merely postulated generalized osteopathy in psoriatics, the serum calcium level, the alkaline phosphatase in the serum and the urinary excretion of hydroxyproline were evaluated in 24 patients with Ps and 24 patients with PA. Moreover, the bone bioptates from 25 patients with PA and 10 patients with Ps were examined histologically and measured morphometrically. The investigations provide evidence for the existence of a generalized "latent" osteopathy in terms of an elevated bone turnover rate without loss of bone volume (high turnover remodelling) in both patients with PA as well as those with Ps without arthritis. As a pathogenetically essential factor shared by dermatosis and "osteopathy", latent vitamin D deficiency and/or D hormone resistance is discussed.

Adult↗
PubMed1990

[Current aspects of fluoride therapy of osteoporosis].

Fluorine has an effect on the bone, it increases both the number and the activity of osteoblasts and, thus, at first leads to an osteoidosis. The mineralization is somewhat lagging behind. This mode of action is best suited for low-turnover osteoporosis. For all other forms of osteoporosis, such as high-turnover osteoporosis, osteoporomalacia and mixed osteopathies, fluorine therapy as the sole treatment is not optimal. In our opinion, it is not the action principle "fluorine" that is insufficient or dangerous, but the indication for this therapy was not given in case of treatment failures or certain side effects. The decisive progress in the treatment of osteoporosis is to be expected from an essentially improved and pathophysiologically oriented differential diagnosis and the resulting differential therapy.

Fluorides↗
PubMed1990

[Psoriatic osteopathy--results of histomorphometric studies].

In 23 patients with psoriatic arthritis and 9 patients with psoriasis without joint involvement, we took bone biopsies from the iliac crest. Histomorphometrical investigations showed that the volume density of the bone was not decreased in either group of patients, but we found a high rate of turnover remodelling. An elevated rate of bone turnover is regarded as the characteristic principle of "psoriatic osteopathy", which--more exactly--should be called "latent osteopathy". Deficiency of vitamin D is discussed as a possible etiological factor.

Adult↗
PubMed1989

[Psoriatic osteopathy].

In order to make evident an up to now only postulated generalized osteopathy in psoriatics in 24 patients with psoriasis and 24 patients with psoriatic arthritis the serum-calcium levels, the alkaline phosphatase in the serum and the excretion of hydroxyprolin in the urine were determined. Moreover, the bone bioptates of 25 patients with psoriatic arthritis and 10 patients with psoriasis were histologically examined and morphometrically measured, respectively. The examinations give evidence for the presence of a generalized "latent" osteopathy in the sense of an increased bone turnover rate without loss of bone volume (high turnover remodeling) in patients with psoriatic arthritis as well as in those with psoriasis without arthritis. As a common pathogenetically significant factor for dermatosis and osteopathy a latent vitamin D deficiency and a D-hormone resistance is discussed.

Alkaline Phosphatase↗
PubMed1989

Osteoarthritis and bone: osteologic types of osteoarthritis of the hip.

To assess prognosis and indications for allografting articular surfaces, osteological examination is of increasing importance. In this study 93 femoral heads of patients with primary osteoarthritis could be differentiated into three osteologic types using histomorphometry: (1) the osteosclerotic type (77% of cases), (2) the hyperostotic type, with excessive neogenesis of bone all over the femoral head and increased formation of osteophytes (10% of cases), and (3) the osteopenic type, with decreased bone mass and features of bone remodelling, a greater occurrence of subchondral cysts, and small osteophytes (8% of cases). Radiological and clinical features to distinguish these groups are given. The consequences for pathogenesis and clinical practice are discussed.

Female↗
PubMed1989

Analyses of the tidemark on human femoral heads. I. Histochemical, ultrastructural and microanalytic characterization of the normal structure of the intercartilaginous junction.

The tidemark as a boundary between non-calcified and calcified articular cartilage has a complicated structure and fulfils various physiological functions. 25 human femoral heads from healthy joints were examined. In non-decalcified preparations three structural components of the tidemark were demarcated: (1) the PAS-positive, proteoglycan-containing tidemark line adjacent to the basal cartilage, (2) the sublinear light-coloured zone and (3) the demarcation line to the calcified cartilage. Using scanning electron microscopy, the tidemark was characterized as an electron-dense impression between hyaline and calcified cartilage. The presence of specific architecture and orientation of collagenous fibres could not be shown. Concentrations of calcium, phosphorus and sulphur could not be detected in the tidemark by means of an X-ray microanalyzer. A morphological model of the tidemark region was established, which represents the intercartilaginous junction as a double layer of substantially and functionally different surfaces.

Adult↗
PubMed1989

Analyses of the tidemark on human femoral heads. II. Tidemark changes in osteoarthrosis--a histological and histomorphometric study in non-decalcified preparations.

Histological and histomorphometric examinations were carried out on 88 human femoral heads, 63 from patients with osteoarthrosis and 25 controls. The changes of the tidemark were found to be multiform in the osteoarthrotic process and could be classified into three degrees of severity. Low-grade tidemark changes were characterized by reduplications of the tidemark and discontinuities of the tidemark line, occurring also in about one third of the controls. Vascular invasion into the tidemark as well as incipient calcification of basal hyaline cartilage were observed in middle-grade tidemark alterations. High-grade changes were distinguished by the disappearance of the tide-mark, advanced mineralization and ossification of basal hyaline and calcified cartilage and finally by the "tidemark and bone bald". Measuring the thickness of intact and osteoarthrotic hyaline cartilage, calcified layer and subchondral bone plate, it was possible to determine some correlations between the tidemark state and the structures measured. Variations in subchondral bone volume could also influence the tidemark and cartilage changes. The important role of the intercartilaginous junction in the pathogenesis and progress of osteoarthrosis is stressed.

Aged↗
PubMed1989

[Loss of bone substance in long-term dialysis--the value of serochemical parameters].

During long-term hemodialysis therapy a loss of bone substance--an osteopenia--may occur. The diagnosis is possible by bone biopsy. We have analyzed the bone metabolism-associated serochemical parameters in patients suffering from osteopenia in comparison with patients with normal bone volume. 21 patients were analyzed: 14 females, 7 males, duration of dialysis 44 +/- 29.9 months, age 47.3 +/- 12.5 years. The serum values of calcium, anorganic phosphate, alkaline phosphatase, pH and c-terminal parathormone are determined. The histological bone examination according to the Delling classification did show following distribution: Type I--0, type II--10, type III--10 (without renal osteopenia--1). A quarter of the patients did show a reduction of the bone mass. The parathormone value was significantly reduced in these patients in comparison with patients without osteopenia. No significant changes could observed in the comparison of alkaline phosphatase, serum calcium, anorganic phosphate and pH value. Our results show that in patients with osteopenia the serum parathormone level is reduced relatively.

Adult↗
PubMed1989

[Clinical significance of beta 2 microglobulin determination in dialysis patients].

In radioimmunological estimation of beta 2-microglobulin significant higher serum values were found in 36 dialysis patients (44.4 +/- 20.3 mg/l) in comparison with healthy probands (1.5 +/- 0.2 mg/l). A significant relation to the duration of dialysis, rest diuresis and serum level of aluminium was found. Significant higher concentrations were observed in patients suffering from pain in the shoulder-limb-region and with ostealgia in other regions, but not in radiological verified destructive arthropathy and spondylarthropathy. The used dialyzers MLW 1.3/1.8 m2 did not eliminate the beta 2-microglobulin from the blood.

Adult↗
PubMed1987

[Principles of differential pathogenesis-oriented therapy of various forms of osteopenia].

From the demonstration of etiopathogenetic mechanisms of osteopenia 7 different histologically and histomorphometrically defined pictures of the state (diseases) of the skeleton are derived. From this 4 different possibilities of the influence on the permanent transformation of the skeleton--the remodeling are the result. The medicamentous support of the blockade or stimulation of osteoclasts and the optimization of the mineralization are the basis of therapeutic considerations. In the light of these pathogenetically orientated treatment strategies the real and at present practicable therapy regimes of the various clinical manifestations of the osteopenia and new beginnings especially also of the therapy of osteoporosis are discussed.

24,25-Dihydroxyvitamin D 3↗