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Biomedical subjects

P F Schmidt

Publications and source records attributed to P F Schmidt.

30 records · Page 2Linked to original sources
PubMed1985

Influence of low and high cadmium diet in normotensive and hypertensive SH-rats.

Normotensive and SH-rats (Münster strain) were fed a cadmium-rich, normal or cadmium-poor diet. The blood pressure was slightly increased in normotensive rats after feeding a cadmium-rich diet and decreased after a cadmium-poor diet. In contrast, in SH-rats blood pressure was decreased after a cadmium-rich and increased after a cadmium-poor diet. This behavior of the blood pressure corresponded with the intra-erythrocytic Ca2+ activities. Whereas the calcium activities increased in the normotensive group after a cadmium-rich diet, the calcium activities decreased in the SH-group after cadmium feeding. It should be pointed out that normally the calcium activities were found to be elevated in SH-rats. Thus, cadmium feeding here had the same effect as a calcium antagonist.

Animals↗
PubMed1985

Distribution patterns of lead in the aortic wall determined by lamma.

Responsible for the controversial view on the role of lead in the development of atherosclerotic lesions seems to be the lack of suitable methods to determine relatively low concentrations of lead inhomogeneously associated to various tissue components. The recent development of the laser microprobe mass analysis (LAMMA) now provides a unique method to precisely determine specific distribution patterns of lead concentrations within substructures of the vascular wall. In contrast to the integrating analysis of atomic absorption spectroscopy (AAS) LAMMA allows a morphologically controlled analysis of the lead content in microsamples (greater than or equal to 1 micron3) with a detection limit of 10(-19) g. Evaluations of specimens of the aortic wall of human autopsy material prepared for LAMMA revealed in the case of a male subject aged 80 years an invariable lead content limited to the adventitia and to the elastic fibers of the media. However, in a female subject aged 35 years a decreasing gradient of lead content was found from the intima to the adventitia including cell nuclei and elastic fibers of the media.

Adult↗
PubMed1984

Assessment of magnesium and aluminum in erythrocytes by the laser microprobe mass analyzer (LAMMA).

The erythrocyte magnesium content was determined using two different analytical systems (atomic absorption spectrometry and the laser microprobe mass analyzer) with specimens from 18 patients with normal renal function and from 10 patients with chronic renal insufficiency. There was a good correlation (r = 0.73) between the two analytical systems. Additionally, the laser microprobe mass analyzer was used to determine the aluminum content of plasma and erythrocytes in specimens from patients who ingested moderate quantities of aluminum hydroxide for several months. Results showed a significant elevation of the plasma aluminum concentration, but a normal erythrocyte aluminum content. The laser microprobe mass analyzer may be useful in studies of mineral metabolism in humans.

Adult↗
PubMed1982

The use of a laser microprobe to identify calcium oxalate in histological material.

Some birefringent renal deposits were found to give the usual histological reactions for calcium oxalate but were soluble in caustic alkalis. Comparison with known oxalate crystals using a laser microprobe mass analyser confirmed the presence of calcium oxalate. Similar crystals were found in liver tissue from a rat poisoned with ethylene glycol.

Aged↗
PubMed1980

Secondary athrocytotic cardiomyopathy--heart damage due to Wilson's disease.

Post-mortem atomic absorption spectrophotometry of the myocardium of a 14-year-old boy revealed a hundred-fold increase in copper. Further electrolyte analysis of the myocardium showed changes corresponding to metabolic heart muscle damage. Ultrastructural examination showed all the feature of a cardiomyopathy at the cellular level. Laser-Microprobe-Mass-Analysis demonstrated an inhomogeneous distribution of copper. An essential factor in the mechanism of death is heart damage.

Adolescent↗
PubMed1980

LAMMA--investigations of biological and medical specimens.

One feature of the Laser Microprobe-Mass-Analyzer (LAMMA) is the analysis of biomedical specimens. This method allows to obtain qualitative and quantitative information about the inorganic and--in a qualified sense--about the organic constituents of microvolumes of thin histological sections or of single cells (e.g. erythrocytes) with a relative sensitivity going down to the sub-ppm range. The paper describes the technical structure and features of the laser-microprobe, its advantages and possibilities, but also its limits in the investigation of biomedical specimens. This will be pointed out by some examples: 1) Analysis of blood from patients suffering from renal insufficiencies (A1 transportation, Fe/Mg ratio of erythrocytes). 2) Pb detection in fetal tissues after maternal Pb intoxication. 3) Analysis of trace elements (detection limits and superposition of organic background from embedding material). 4) Analysis of isotopes and molecules. The present contribution is not so much a discussion of medical problems, but mainly a discussion about the methodical and practical use of the laser microprobe.

Aluminum↗
PubMed1979

Effects on reflex bladder activity of chemical stimulation of small diameter afferents from skeletal muscle in the cat.

In anesthetized cats selective activation of fine muscle afferents of the hindlimb by KCl or bradykinin (Brad.) induced reflex changes in the urinary bladder. The nature of the reflex responses depended on the functional state of the bladder: they were excitatory when the bladder was quiescent and inhibitory during large, slow, rhythmic micturition contractions. Selective activation of large muscle primary afferents by succinylcholine was ineffective. All reflexes disappeared after cutting the sciatic or the pelvic nerves. Transection of the hypogastric nerves to the bladder had no effect.

Animals↗
PubMedDate not supplied

Oxalate-induced encephalitic reactions to polyol-containing infusions during intensive care.

Fifteen of 5800 neuropathologically examined brains showed oxalosis with an intense inflammatory reaction comparable to ethylene glycol intoxication. All patients had received intensive care therapy with infusions of high amounts of xylitol, sorbitol, mannitol, or fructose, mostly together with glucose. The encephalitic reaction induced by calcium oxalate crystals was manifested by clinical symptoms of cerebral damage. A genetically fixed polyol intolerance is hypothesized to explain polyol-induced oxaloses in brain, kidney, and partly also in myocardium.

Adolescent↗