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Biomedical subjects

A Schulz

Publications and source records attributed to A Schulz.

At least 217 records · Page 12Linked to original sources
PubMed1981

Fast hardening aminoacid-solution as potential carrier of chemotherapeutic agents in the treatment of chronic osteomyelitis.

Report about an aminoacid, which hardens quickly in liquid environment. It is highly suitable as carrier of chemotherapeutic agents. In-vitro tests show an antibiotic inhibitory activity of different compounds for at least 41 days. According to in-vivo experiments in 17 rats the new substance is replaced in the bone and in soft tissues by fibrous tissue; the antibiotic activity is released slowly. This offers a new carrier which is suitable for occlusion of cavities. The instillation of the new amino-acid (Ethibloc) combined with antibiotics could be a new treatment for chronic osteomyelitis.

Animals↗
PubMed1980

[Peripheral vestibular vertigo (author's transl)].

In 88 patients with benign paroxysmal postural vertigo and repeated attacks of vestibular vertigo the clinical and electronystagmographic findings were evaluated in a retrospective study. After an interval of at least two years 16 patients with paroxysmal postural vertigo were symptom-free 39 had rare or (and) tolerable vertigo, 30 frequent and (or) disturbing recurrent postural vertigo. Five patients showed transition into spontaneous recurrent attacks of vertigo. Out of 37 patients with single vestibular vertigo after an interval of at least 4 weeks 9 had unilateral caloric unresponsiveness, 11 hyporesponsiveness, 11 spontaneous nystagmus and 6 normal findings. 58 patients with recurrent vestibular vertigo could be differentiated into two groups: 29 with signs of labyrinthine damage and 29 with persistent normal findings in the interval even after many years of the disease. The two groups were significantly different in their age of manifestation. It is thus justified to separate functional from organic vestibulopathies. Not even in the group of organic vestibulopathy was there any clear-cut evidence of general vascular disease as the underlying cause.

Adult↗
PubMed1979

Histomorphometric analysis of bone changes in surgically proven primary hyperparathyroidism and nephrolithiasis--the importance of bone biopsy in diagnosis.

The morphologic changes in trabecular bone were studied in 60 patients with surgically proven hyperparathyroidism and in 69 patients with nephrolithiasis. The hyperparathyroid bone lesions showed substantial variation in their extent. Four, typical stages were defined. The structure of trabecular bone remained intact in most cases. Bone turnover is significantly higher in the patients with primary hyperparathyroidism. Fifty percent of all patients with nephrolithiasis had bone changes similar to those found in the surgically proven hyperparathyroidism group. In 50% of so-called asymptomatic cases of hyperparathyroidism, the iliac crest biopsy is a useful supplement to clinical and hormonal data in deciding whether to operate on the parathyroid glands. In about 45% of cases, however, no definite diagnoses is possible. The determination of serum parathyroid hormone in primary hyperparathyroidism has a greater importance for diagnostic purposes than morphologic investigation of the bone biopsy.

Adolescent↗
PubMed1978

Morphology of osteosarcoma: new qualitative and quantitative investigations.

Results on seven cases of osteosarcoma are reported, based on new morphologic methods and quantitative procedures. Tumor tissue was embedded without prior decalcification in plastic and sectioned. Imprint cytology preparations were produced from fresh tumor tissue, and cell nuclei were measured with an electronic image analysing computer system. The loss of differentiation seen in osteosarcomas differs among osteoblasts, osteocytes, and osteoclasts. The differentiation of osteoclasts, namely their resorptive characteristics, disappears relatively early. Tumor osteocytes show loss of differentiation in their osteocyte processes. The new formation of tumor bone tissue remains in the near normal range of volume density when nuclear polymorphy is limited. The formation of ground substance and mineralization are apparently closely couplet to one another, since in our cases mostly ordered osteoid seams were observed. The capacity for mineralization of bone tissue is lost with marked polymorphy. The significance of these results for diagnostic statements and therapeutic consequences will be further discussed in long term studies.

Adolescent↗
PubMed1978

[The coincidence of Paget's disease and an immunoblastic sarcoma (author's transl)].

Malignant change is to be expected in about 1% of patients with Paget's disease. Usually these are osteosarcomas. Fibrosarcomas, benign and malignant giant cell tumours and chondrosarcomas are less common. The present case concerns the development of an immunoblastic sarcoma in the humerus, which was affected by Paget's disease. Only one other similar case is recorded in the literature. Other myelogenous tumours, such as plasmocytomas, are very rare in association with Paget's disease. Consequently there is no evidence for a causal connection between Paget's disease to these tumours, whereas sarcomas arising from bine tissue may be regarded as a form of malignant degeneration of Paget's disease.

Bone Marrow Diseases↗
PubMed1978

Ultrastructural study of tumor cell differentiation in osteosarcoma of jaw bones.

Tw osteosarcomas of jaw bones have been studied by electron microscopy. The objectives were to examine the specific cell types in relation to functions and ultrastructural features, and to examine matrices produced by tumor cells. The osteosarcoma cells were subdivided into four cell types: anaplastic, chondroblastic, osteoblastic, and osteocytic--giant cells were not considered in the present investigation. Compared to normal bone cells, no specific sign of malignancy was found. However, tumor cells seem to lose functional abilities, i.e. a modification of matrix. Consequently, tumor matrix has altered organic and inorganic components with impairment of collagen maturation and matrix mineralization. The alteration in both processes may be related to a diminished production of proteoglycans. The cytogenic hypothesis of a tumor stem cell may be supported by the identification of anaplastic osteosarcoma cells resembling immature reticulum cells. One may speculate on transformation of this cell type as a genetically predetermined osteoprogenitor cell of malignant potential.

Adult↗
PubMed1977

[Paget's disease of bone: ultrastructure and cytogenesis of osteoclasts (author's transl)].

The cytogenesis of giant osteoclasts in Paget's disease of bone was studied by means of electron microscopy. 26 iliac crest biopsies were made and divided for light and electron microscopic investigation. A special procedure was used for electron microscopic preparation of bone without previous decalcification. Paget osteoclasts are characterized by their high content of nuclei. Several nuclei may show paracrystalline inclusions pointing to a possible virus infection of these cells. Giant osteoclasts have an increased mobility and a high resorptive activity, manifest by the dissection of bone fragments from endosteal bone surfaces. Cell membrane interdigitations between mononuclear cells and osteoclasts occur as a morphologic concomitant of cell fusion. Frequent occurence of such cell membrane contacts seem to indicate an increased tendency to cell fusion among the mononuclear precursors of Paget-osteoclasts. Precursor cells are located in the pericapillary region, and morphologically resemble pericytes. The assumption of an increased rate of cell fusion amoungst the precursor cells of osteoclasts might explain the development of giant osteoclasts in this disease. Further studies of the paracrystalline nuclear inclusions of Paget-osteoclasts are necessary to determine whether this process can be considered to be a cytopathogenic effect of virus infection.

Aged↗
PubMed1977

Advances in the morphological diagnosis of bone tumours: cytology, cytochemistry, acrylate embedding and electron microscopy (author's transl).

An exact morphological diagnosis of bone tumours is the prerequisite for selective treatment. In a given case this may present great difficulties, partly because of the rarity of a tumour group and thus lack of experience, partly faulty removal of the specimen and unsatisfactory further technical handling. Progress can be expected only by widening the spectrum of methods by using modern morphological tests. In a programme using imprint cytology, cytochemistry, rapid section, histochemistry, paraffin, non-decalcified embedding in acrylate and electron microscopy it was demonstrated in 78 cases of bone tumour (seen over a period of two years) that with these tests, especially cytology, cytochemistry and non-decalcified acrylate histology, significant improvement can be obtained in the morphological diagnosis of bone tumours. In addition, new lights on cytogenesis and pathogenesis of these tumours and possible points of attack of cytostatic treatment are provided.

Adolescent↗
PubMed1977

Odontogenic myxoma - clinical concept and morphological studies.

Our experience with the odontogenic myxoma of the mandible is presented. Although it is a benign, slow growing neoplasm, it is locally aggresive. Patients rarely complain of any symptoms produced by this tumor. Morphological studies included enzymes histochemistry, as well as light and electron microscopy. Two major types of tumor cells were identified. One resembled a mature fibroblast, while the other had the morphological and functional criteria of a so-called myxoblast. We would recommend therapy comprising wide resection and consecutive primary osteoplasty.

Adolescent↗