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Biomedical subjects

I Schwörer

Publications and source records attributed to I Schwörer.

17 recordsLinked to original sources
PubMed1985

[The obscure primary tumor].

The imaging techniques and their results were analysed in 202 patients in whom a primary tumour was diagnosed only at autopsy. The main cause for failure to find the primary tumour was misinterpretation by the radiologist. Pure description offers no more than can be seen by a skilled clinician. The examination should lead to a diagnosis; even a suspicion should be indicated and one should insist on additional measures for follow-up or for obtaining a diagnosis. Improved diagnosis due to the introduction of sonography and CT has only been partially achieved. Malignant pulmonary tumours are the most commonly overlooked lesions and represent 30% of undiagnosed tumours. They are the most frequent primary tumours giving rise to cerebral and bone metastases.

Adult↗
PubMed1983

[Lead deposits in bone--the roentgen picture as a demonstration method?].

Current concepts concerning the deposition, distribution and radiological demonstration of lead in the skeleton were investigated in five series of rats; some of these were young and others more than a year old. 10 mg of lead acetate/kg body weight were administered over a period of five to 41 days, giving a minimum of 8.4 mg and maximum of 40.4 mg of lead. A comparable control group was given similar amounts of sodium acetate. The distribution and concentration of lead in the femur was determined by the use of 210Pb. Contact autoradiographs showed band-shaped lead accumulation in the endosteal and periosteal growth regions. The degree of darkening depended on the amount of lead administered and permitted a rather coarse quantitative relationship to be drawn. Measurements of radioactivity produced similar distribution patterns. The relationship of lead concentration of epi- and metaphysis to the diaphysis averaged 2:1. The factor mainly responsible for lead deposition depended on the metabolic potential of the tissue, which itself depends largely on the growth regions. Radiologically, there was definite evidence of demineralization in the areas of lead deposition; this could be confirmed histologically by lack of trabeculae, thinning of the cortex and destruction of bone matrix. Despite its much greater absorption co-efficient, the tiny quantities of lead, compared with the bone mass (even in the highest concentrations in our experiments) cannot be detected radiologically. Biophysical calculations have been made which indicate that similar conditions occur in man. Radiological examination of the skeleton, which is used as a screening method for chronic lead poisoning, is not suitable for this purpose.

Absorption↗
PubMed1981

[Radiological findings in the hypopharynx after laryngectomy (author's transl)].

The hypopharyngiogram is a necessary investigation for diseases of the larynx. It is particularly valuable following laryngectomy, since the altered anatomy makes endoscopy difficult and enable only endoluminal tumour to be seen. Following operation and radiotherapy, the radiologist is also confronted by appearances which may be difficult to interpret. A knowledge of the operative technique makes correct diagnosis possible. The radiological signs of malignancy and benignancy have been evaluated and are demonstrated. The result suggests that it is necessary to modify radiological concepts. The possibility of curing early recurrences makes radiological observation very important during follow-up.

Deglutition Disorders↗
PubMed1980

[Elimination of lead from rats under biological stress, and application of Na2Ca-EDTA (author's transl)].

It is currently thought that lead is released from organic depots in response to internal or external stress to the organism. Using young Wistar rats, we were unable to confirm this view. Chronic lead levels, persisting over a period of 20 days, were achieved by the intraperitoneal injection of labelled (210Pb) lead acetate into rats (5 mg/kg body weight). The animals were divided into four groups. One group was maintained normally as a control, while two others were subjected to stress, i.e. starvation and injection of an autolysate of bacteria, respectively. All three of these groups showed identical behaviour with respect to total body radioactivity, femur radioactivity (representing the chief skeletal depot), and excretion of radioactivity. The fourth group received Na2Ca-EDTA (sodium salt of the calcium chelate of ethylenediaminetetraacetic acid). The decrease of total body radioactivity and femur radioactivity, and the relative excretion of 210Pb had almost levelled out by about 14 days, and was related mainly to the elimination of lead from the bones (in parenchymatous organs, the cell membrane forms a barrier to the therapeutic removal of intracellular lead). This illustrates the effectiveness of early treatment in lead poisoning, and the ineffectiveness of continuous therapy.

Animals↗
PubMed1978

[Band-like osteoporosis (author's transl)].

Atrophy of the skeleton due to inactivity may have two types of radiological change: diffuse decalcification and band-like porosis in the zones involved by previous growth. The type of decalcification is evidently determined by the vascular anatomy of the bones. This results in localised differences which are independent of age, the type of trauma or the duration of immobilisation.

Achilles Tendon↗