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Biomedical subjects

E Neumann

Publications and source records attributed to E Neumann.

At least 109 records · Page 6Linked to original sources
PubMed1980

Kinetic models suggest bimolecular reaction steps in axonal Na+-channel gating.

Abstract kinetic models that can successfully simulate the ion-permeability features of axonal Na+ channels suggest the presence of bimolecular reaction steps in the activation of the channels. A chemically plausible interpretation of minimum complexity is described. The implied chemical formalism is highly suggestive of an activator-controlled gating system with strong similarities to the acetylcholine-regulated system. Conformational changes that underlie the ion-conductance changes are suggested to possess a greater sensitivity to the membrane field in axonal parts of excitable membranes than at synaptic parts. This would allow axonal permeability changes to be energetically regulated more conservatively than is observed for synaptic ion channels. Axonal K+ channels with delayed activation kinetics would serve to reverse the increase in membrane permeability to Na+ with a minimum of chemical dissipation.

Axons↗
PubMed1980

Non-specific positive test results to syphilis in dermatological diseases.

Sera from 3028 patients attending a dermatological clinic were examined by the fluorescent treponemal antibody (FTA) test, the fluorescent antibody-absorbed (FTA-ABS) test, the Venereal Disease Research Laboratory (VDRL) test, and Kolmer's test. Eleven cases of late syphilis were found. Sera from 63 (2.08%) of the remaining 3017 patients showed non-specific results; these were found more frequently in patients with pyodermas, neoplasms, acne, mycoses, crural ulceration, and psoriasis than in those with other diseases. No non-specific results were observed in patients with bullous skin diseases and only a few in patients with viral skin diseases and chronic lupus erythematosus. The test producing the most non-specific results was the FTA test, followed by the FTA-ABS test, the VDRL test, and Kolmer's test.

Antibodies, Bacterial↗
PubMed1980

Some unusual findings in porokeratosis Mibelli.

Light microscopy in a case of unilateral porokeratosis Mibelli revealed a cyst-like dilatation in the upper corium containing two cornoid lamella complexes. Among other findings, elastic globes as part of thickening and fragmentation of elastica, which in this case may be related to microangiopathia deserve to be mentioned.

Adolescent↗
PubMed1979

[Course and intensive treatment of acute falciparum malaria (author's transl)].

The case of a nineteen-year-old women with the cerebral form of malaria tropica is reported. She showed hyperpyrexia, abdominal manifestations, haemolysis and disseminated intravascular coagulation. Cerebral symptoms amounting to grade IV encephalopathy occurred. The patient responded rapidly to the administration of chloroquine, anticonvulsants, dextran, corticosteroids, antipyretics, blood and antithrombin III and her symptoms had almost completely vanished one week after the onset of therapy.

Acute Disease↗
PubMed1979

Demonstration of vitamin B12 deficiency by a simple cytochemical reaction in the peripheral blood smear.

A simple, rapid and inexpensive cytochemical method for the detection of vitamin B 12 deficiency was applied in several types of anemias and matched with the levels of vitamin B12 and folic acid in the serum of the patients. It was found that in patients with low vitamin B12 levels the stained erythrocytes and the erythroid precursors showed a yellowish brown discoloration, which was not detected in folic acid deficiency and all other types of anemias. This test therefore may be used for differentiation between B12 and folate deficiency whenever megaloblastic anemia is diagnosed.

Anemia, Megaloblastic↗
PubMed1979

Kinetics and mechanism for the conformational transition in p-guanidinobenzoate bovine trypsinogen induced by the isoleucine-valine dipeptide.

The interaction between p-guanidinobenzoate-trypsinogen and the isoleucine-valine dipeptide has been investigated by temperature-jump relaxation spectrometry. Using the absorbance at 281 nm the concentration dependence of the relaxation parameters is consistent with the conventional induced-fit model: rapid ligand binding coupled to a slower intramolecular change; some alternative mechanisms can be excluded. At 296 K, 0.1 M Tris HCl, pH = 7.4, the dissociation equilibrium constant for the overall process is K = 5.1(+/- 0.2) X 10(-5) M; for the binding step K1 = 2.3(+/- 0.3) X 10(-3) M and the rate constants for the structural change are k2 = 26(+/-6)s-1 and k-2 = 0.61(+/- 0.04)s-1; the overall dissociation reaction enthalpy is delta H0 = 26(+/-6)KJmol-1 and the reactiom entropy is delta S0 = 4(+/- 20) kJ-1 mol-1. In combination with CD and X-ray crystallographic data, the results of this study suggest that the binding of the dipeptide to a trypsinogen-like, partially disordered conformation induces a transition to a trypsin-like highly ordered structure.

Animals↗
PubMed1979

[Anemias significant in occupational medicine].

The role of anaemia in occupational medicine is reviewed briefly. Although anaemia is an infrequent symptom, it may be important by its severeness. Irreversible bone marrow failure following exposition to benzene, is discussed more in detail and finally the importance of evaluating professional exposition to potentially myelo-toxic compounds in every patient, is emphasized.

Anemia↗
PubMed1979

[Regulation of erythropoiesis].

Following a brief review of the factors regulating erythropoiesis, which have enhancing influence only, an inhibiting factor with low molecular weight is presented. This non-toxic factor derived from normal human erythrocytes is inhibitory to the 59Fe incorporation into mouse erythrocytes in vivo and also to the 3H-TdR uptake into fetal mouse erythroblasts in vitro.

Animals↗
PubMed1979

[Serum ferritin and its diagnostic significance in iron metabolism disorders].

Aim of the study was the evaluation of the diagnostic value of the parameters of iron metabolism in normal adults and also in patients suffering from uncomplicated iron deficiency, iron overload due to repeated blood transfusions, malignant lymphoma and Crohn's disease. In these patients, the determination of serum ferritin increased the diagnostic efficiency only in poly-transfused patients with iron overload.

Anemia, Hypochromic↗
PubMed1979

[Indication and value of erythrokinetic examinations in anemia].

As erythrokinetic studies are time consuming and costly, this technique should only be done to provide information which is unavailable through simpler tests. By means of discussion concerning the methodological procedure and obtainable information, the indications for erythrokinetic investigations with Cr 51 and Fe 59 are derived. Since the results should be interpreted together with the clinical and haematological findings, a close cooperation of the departments of nuclear medicine and haematology would be essential.

Anemia↗
PubMed1979

[Acute hemolysis in polycythemia vera].

The clinical course of fulminant haemolysis in a 54 year old patient with polycythaemia vera is described. Haemolysis was due to a complement-activating cold-autoantibody of the IgM class. A pathogenetic association between polycythaemia vera as a myeloproliferative disorder and autoimmune-haemolysis is discussed.

Acute Disease↗