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Biomedical subjects

G Erdmann

Publications and source records attributed to G Erdmann.

At least 37 records · Page 2Linked to original sources
PubMed1983

Perfusion of the cervical spinal cord in situ of adult rats using a perfluorocarbon emulsion.

A method was developed for the perfusion of the cervical spinal cord of adult rats through the supplying arteries. A medium containing perfluorotributylamine as an oxygen carrier was used. The electrophysiological responsiveness was continuously monitored; pO2, pCO2, pH, Na+ and K+ were intermittently measured in the medium. The perfused cord maintained its responsiveness for more than 5 h. No changes in its structure became apparent in electron micrographs.

Animals↗
PubMed1981

Intraspinal distribution and reaction in the grey matter with tetanus toxin of intracisternally injected anti-tetanus toxoid F(ab')2 fragments.

Anti-tetanus toxoid F(ab')2 fragments were purified using immune-affinity chromatography on tetanus toxoid-Sepharose. Fragments were labeled with 125I. Labeled or non-labeled fragments were injected into the intrathecal space of rats. The labeled fragments were found in the spinal cord outside but not inside neurons. Tetanus toxin was injected into a muscle and 36 h later labeled fragments were injected intracisternally. After another 24 h the label was elevated in the spinal cord half segments giving neural supply to the injected muscle and in these half-segments the label was concentrated around some alpha-motoneurons. [125I]Tetanus toxin was injected into a muscle and at different times thereafter non-labeled fragments were injected intracisternally. The development of hindlimb rigidity but not the accumulation of [125I]tetanus toxin in alpha-motoneurons was prevented by early intracisternal injection of fragments. Injection of fragments after the appearance of hindlimb rigidity did not revert the rigidity but prevented the further development of symptoms. It is concluded that an action of tetanus toxin inside alpha-motoneurons is of no importance for the development of motor symptoms in clinical tetanus. The data suggest that in order to evoke spinal symptoms of toxicity tetanus toxin has to reach interneurons by transneuronal migration. In the very early stages of clinical tetanus the intrathecal injection of fragments may be useful.

Animals↗
PubMed1981

[Atopic dermatitis in children (author's transl)].

Atopic dermatitis is a common chronic skin disorder in children of atopic constitution. There is a great variety of opinions regarding the possible causes, diagnostic measures and treatment of the disease. Important problems are skin testing, investigation of immunoglobulines E (RIST and RAST), food allergy in infants, elimination of allergens and hyposensitization. Symptomatic treatment often proves to be very effective, especially topical administration of corticosteroids. As a rule hospitalisation is not desirable. Sometimes, however, proper symptomatic treatment needs a lot of time and skill so that adequate nursing care in hospital is advisable. The mother can be instructed there, perhaps realizes prompt results and may obtain some rest after distressing situations at home.

Adrenal Cortex Hormones↗
PubMed1978

Interaction between physiological and cognitive determinants of emotions: experimental studies on Schachter's theory of emotions.

This study investigated the interaction between physiological arousal and situation-derived cognitions in the determination of feeling states that is proposed in Schachter's theory of emotions. The degree of bodily arousal was varied by disguised oral administration of a placebo or the sympathicomimetic agent ephedrine. The situational circumstances were varied by instructions offering cues for (a) no emotions ('neutral' control), or the feeling states called (b) 'anger', (c) 'happiness', and (d) anxiety'. The subjects were 72 male students. The dependent variables were blood pressure, heart rate, a list of bodily symptoms, and an adjective check list. The results within the 'anger' and 'happiness' condition were in accordance with Schachter's theory: depending on the type of situation, ephedrine-induced arousal either decreased or increased positive descriptions of mood. The emotional effects of the 'anxiety' condition, however, were independent of the drug-induced arousal level. Contrary to Schachter's theory, anxiety reactions occured also in a state of low physiological arousal and did not increase with increasing arousal.

Anger↗
PubMed1978

[Experimental study on the effect of ephedrine in an anger-provoking situation].

The purpose of this study was to investigate the effects of ephedrine-induced sympathetic arousal on emotional reactions in an anger-provoking situation. The effects of ephedrine were compared with a placebo condition while the effects of the anger-situation were compared to a neutral control situation. 60 male students were randomly assigned to one of the four conditions of the two-factor design. The dependent variables were various peripheral-physiological measures and self rating of physical and emotional states. Both independent variables were found to be effective. Contrary to expectation, ephedrine decreased subjective emotional reactions to the anger-provoking situation rather than increase it. Methodological problems and possible conclusions about the role of sympathetic arousal for emotional reactions are discussed.

Adult↗
PubMed1977

Histoautoradiography of central nervous system in rats with generalized tetanus due to 125I-toxin.

Rats were injected i.v. with 125I-tetanus toxin. In autoradiographs of the spinal cord radioactivity was found over the pericarya and in the surroundings of the motoneurones whereas grain density was less over their nuclear region. In addition, pericarya in the lateral horn of the thoracic region and also the bipolar cells of the spinal ganglia contained radioactivity. The central part and the dorsal horns of spinal cord, and the white substance did not show any appreciable radioactivity. Within the medulla oblongata, clusters of large cells representing motor nuclei, as well as some fibre tracts close to them, contained 125I. Forebrain and cerebellum remained free. According to its histoautoradiographic appearance, generalized tetanus can be described best as a combination of multiple local tetani.

Animals↗
PubMed1976

Comparative autoradiographic and metabolic study of delta8- and delta9-tetrahydrocannabinol in the brain of the marmoset Callithrix jacchus.

The label distribution in the brain of the marmoset Callithrix jacchus following intravenous application of radioactively labeled delta8-tetrahydrocannabinol (delta8-THC) and delta9-THC is investigated by autoradiographic technique. Accumulations of label are observed in nuclei concerned with motor function, in the optic and acoustic pathways, and a few other structures. Of the two hydroxylated isomeres which were shown to be equally psychoactive the brain concentration of 11-OH-delta9-THC was found to be about 3 times higher as compared with 11-OH-delta8 THC, which may explain why delta9-THC is more potent than delta8-THC. More than 90% of the radioactivity found in the brain can be attributed to the THCs and their 11-hydroxylated isomeres. Polar metabolites are almost completely absent from the brain.

Animals↗
PubMed1976

125I-labelled botulinum A neurotoxin: pharmacokinetics in cats after intramuscular injection.

1. On unilateral injection of sublethal doses of 125I-botulinum A neurotoxin (BTA) into one gastrocnemius muscle of the cat we found after 48 h: a) A disto-proximal gradient of radioactivity (RA) had developed in the sciatic nerve of the injected side. b) The ventral roots of the spinal cord half segments supplying the injected muscle showed a higher RA than the ventral roots of the contralateral control side. c) The spinal cord half segments innervating the injected muscle had a RA much higher than the corresponding segments of the contralateral side. However, a small rise of RA was also observed in the contralateral half segments. 2. In histoautoradiographs of the (ligatured) ventral roots the RA was strictly confined to the intraaxonal space of a few nerve fibres. 3. On injection of equal doses of 125I-BTA into either gastrocnemius muscle we found after 38 h: a) Direct stimulation of only one of the injected muscle caused the RA to reach a higher level in the spinal cord half segments ipsilateral to the stimulated muscle than in the spinal cord half segments of the non-stimulated side. b) Unilateral stimulation of one gastrocnemius nerve under the influence of gallamine or unilateral antidromic stimulation of the dorsal roots L7, S1 failed to cause a difference in RA between stimulated and non-stimulated side.

Animals↗
PubMed1976

[Autoradiographic studies on the distribution of 3H-pyrithioxine in monkey and mouse (author's transl)].

Monkeys and mice received oral and i.p. doses of 3H-labelled pyritinoldihydrochloridemonohydrate (3H-pyrithioxine; Encephabol) and the distribution of radioactivity in the brain and in other organs was investigated by autoradiography. The heaviest label accumulation was present in the pituitary gland. In the monkey the distribution of radioactivity in the brain and in the submandibular gland was different from the distribution found in these organs in the mouse, which may be attributed to the different radioactive metabolites of pyrithioxine produced by the two animal species. Prior to elimination from the body pyrithioxine was completely transformed into metabolites.

Administration, Oral↗
PubMed1975

Intraaxonal and extraaxonal transport of 125I-tetanus toxin in early local tetanus.

The distribution of radioactivity in the sciatic nerve, the spinal ganglia, the ventral roots and the spinal cord was studied by means of histoautoradiography after injection of 125I-labelled tetanus toxin into gastrocnemius muscles of cats. In the sciatic nerve the major part of the radioactivity was found in the epineurium, but some axons also contained radioactivity. In the ventral root the radioactivity was strictly confined to a few axons; no radioactivity was found in other parts of the ventral root. In the spinal cord the radioactivity was confined to a few motoneurones where it was found in the soma as well as in the dendrites. Transient cooling of the ventral roots prevented the ascent of radioactivity into the spinal cord. Colchicine and vinblastine, after local application to the sciatic nerve, reduced the amount of radioactivity found in the ventral roots and in the spinal cord. However, the same effect was also obtained but to a lesser degree with lumicolchicine. It is concluded that the intraaxonal compartment is involved in the neural ascent of tetanus toxin into the spinal cord.

Animals↗