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A Baumgartner

Publications and source records attributed to A Baumgartner.

At least 91 records · Page 5Linked to original sources
PubMed1993

The influence of sleep deprivation on thyroid hormone metabolism in rat frontal cortex.

The effects of 24 h sleep deprivation (SD) on central thyroid hormone metabolism were investigated in rat frontal cortex. SD induced a significant rise in the activity of iodothyronine type II 5'-deiodinase (5'D-II), which catalyzes the conversion of thyroxine (T4) to triiodothyronine (T3) in the rat central nervous system (CNS). Tissue concentrations of T4 remained unchanged, whereas levels of T3 increased to more than 150% of the corresponding levels measured in control rats. Serum concentrations of T4 and T3 were also significantly enhanced by SD--an effect that has previously been described in depressed patients having undergone the same procedure. These results suggest that SD can dramatically increase T3 concentrations (and possibly function) in rat CNS. Whether or not these findings are of relevance in regard to the well-known antidepressant effect of SD in psychiatric patients with major depressive disorders remains to be established.

Animals↗
PubMed1993

Influence of partial sleep deprivation on the secretion of thyrotropin, thyroid hormones, growth hormone, prolactin, luteinizing hormone, follicle stimulating hormone, and estradiol in healthy young women.

The influence of partial sleep deprivation during the second half of the night on the secretion of thyroid stimulating hormone (TSH), thyroxin (T4), free T4 (fT4), triiodothyronine (T3), prolactin (PRL), growth hormone (GH), luteinizing hormone (LH), follicle stimulating hormone (FSH), and estradiol (E2) was investigated in 10 healthy young women. Blood samples were drawn at hourly intervals over a 64-hour period (i.e., 3 consecutive days and nights). During night 2, all subjects were awakened at 1:30 a.m. During partial sleep deprivation, TSH concentrations increased significantly and remained elevated throughout the following day. Levels of T4, fT4, and T3 were enhanced during the partial sleep deprivation hours only, and changes in these hormones seemed to be independent of TSH. PRL levels decreased, LH and E2 concentrations increased, and GH and FSH secretion remained unchanged during partial sleep deprivation. This pattern of change of different endocrine axes during partial sleep deprivation resembles those seen after total sleep deprivation, suggesting that similar neurochemical changes are induced by both forms of antidepressant therapy. The late evening GH peak occurred almost exclusively before the onset of sleep. Partial sleep deprivation did not influence the chronobiological profiles of any of the hormones investigated. The chemical changes underlying these alterations are speculated to involve enhancement of central norepinephrine and dopamine activity with a concomitant increase in the activity of the sympathetic nervous system.

Adult↗
PubMed1993

A method for typing Listeria monocytogenes strains by classification of listeriocins and phage receptors.

A method for typing Listeria monocytogenes (L.m.) strains was developed which is based on two different approaches. First, strains were classified according to the phage receptors specific to their mitomycin-induced prophages. The frequency of lysogenic strains ranged between 63 and 80%, depending on the serotype. For non-lysogenic strains, a reversed phage-receptor analysis was applied based on the susceptibility of the strains to be typed against bacteriophages from selected, inducible indicator strains. As a second method, typing of mitomycin-induced listeriocins was shown to be practicable as well. By this approach, it was possible to distinguish 11 different listeriocins when using a set of 7 selected indicator strains. Only two of these listeriocins were probably produced by L.m. strains of serotype 4b. A combination of the two approaches described raises the number of types. When applied to 20 human isolates of L.m. belonging to serotype 4b, 17 different types were demonstrated. 46 L.m. strains of serotype 1/2b could be differentiated into 38 types of which 18 clinical isolates represented 17 different types. 26 L.m. strains of serotype 1/2a isolated from various food products showed a large heterogeneity, with 22 different types. The power of discrimination of the method outlined recommends its application in epidemiological investigations.

Bacterial Typing Techniques↗
PubMed1993

Enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies against Salmonella enteritidis in chicken blood or egg yolk.

Tracing of flock infection remains one of the most serious unsolved problems of controlling salmonellosis in poultry. In order to overcome this problem, a serological test kit for the detection of antibody to Salmonella enteritidis (1, 9, 12:[f], g, m, [p]:[1, 7]) in chicken flocks was developed. In this study, samples of antisera and the yolk of eggs from different chicken flocks were tested with the ELISA kit, and the resulting flock profiles were compared. The test system clearly allowed a differentiation between flocks which were positive and flocks which were negative for S. enteritidis. Sera from stocks infected with S. typhimurium (1, 4, (5), 12:i:1, 2) or S. heidelberg (1, 4, (5), 12:r, 1, 2) were also analysed in order to determine the relative cross-reactivity in the test. No false-positive results could be shown in the case of S. heidelberg; cross-reactions with antibodies against S. typhimurium were found in 2.5% to 10% of the samples from a particular flock. The test kit could also be used for the analysis of egg yolk samples without time-consuming purification procedures. Specific antibodies were detected in high dilutions of positive egg yolks, thus enabling a rapid screening for S. enteritidis-positive chicken flocks.

Agglutination Tests↗
PubMed1993

[Thyroid hormones and depressive disorders--clinical overview and perspectives. Part 2: Thyroid hormones and the central nervous system--basic research].

This paper briefly reviews present knowledge on the uptake, distribution, metabolization, and functions of thyroid hormones in the central nervous system. So far, multiple isolated effects of these hormones could be shown; e.g. a modulation of noradrenergic, serotonergic, and dopaminergic receptor function, and an influence on second messenger, calcium homeostasis, axonal transport mechanisms, and morphology. All these effects are, however, highly specific with respect to brain area and both the biochemical mechanisms and the physiological importance are poorly understood. Antidepressants and neuroleptics influence thyroid hormone metabolism in the CNS. The respective effects depend on the area under investigation, the circadian rhythm, and the specific drug. Future research should investigate primarily the biochemical mechanisms of thyroid hormone action on the central nervous system. Furthermore, it seems worthwhile to examine whether or not the different effects of psychopharmacological drugs on CNS thyroid hormone metabolism are involved in their mechanisms of action.

Brain↗
PubMed1993

[Thyroid hormones and depressive disorders--critical overview and perspectives. Part 1: Clinical aspects].

This review gives a critical synopsis of the literature on the interaction between thyroid hormones and depressive illness, a phenomenon that has been well-known for over 100 years. Possible perspectives for clinical practice and research are discussed. The most relevant conclusions and hypotheses being as follows: 1. Thyroid hormone disorders (hypo- and hyperthyroidism) may induce almost any psychiatric symptom or syndrome. However, no disease of the thyroid causes symptoms typical of a specific diagnosis. 2. Depressed patients are euthyroid, at least in terms of their laboratory values. Abnormal values are all not specific for any psychiatric diagnosis. They are probably due to intervening variables such as stress or weight loss, or simply to methodological problems. 3. Attempts to treat depressive patients with TRH or T3 have not produced any results of clinical relevance. However, some preliminary reports of a prophylactic effect of high-dose thyroxine in previously resistant "rapid-cycling" patients are most promising. 4. All antidepressant and prophylactic therapies (antidepressant drugs, sleep deprivation, ECT, lithium, and carbamazepine) affect thyroid hormone concentrations. During treatment with antidepressants, carbamezepine, and lithium, these changes are significantly correlated to clinical response.

Depressive Disorder↗
PubMed1992

Thyroid hormones and depressive illness: implications for clinical and basic research.

It has been well-known for at least 100 years that both hypo- and hyperthyroidism may cause almost any psychiatric symptom, depending on the severity of the illness. No thyroid disorder, however, induces symptoms that are specific for a psychiatric disorder. Laboratory tests show depressed patients to be euthyroid. Any abnormalities that have been found, such as slightly elevated T4 levels or decreased T3 or TSH concentrations, have frequently failed to be replicated and do not fit any endocrinological diagnosis. They could reflect either "intervening factors" such as stress, methodological problems or a disturbance of central thyroid hormone metabolism. All antidepressant therapies (antidepressant drugs, carbamazepine, lithium, electroconvulsive therapy and sleep deprivation) have a marked influence on peripheral thyroid hormone levels. In particular, decreases in serum T4 and rT3 levels are often correlated to antidepressant response, suggesting that an effect on central thyroid hormone metabolism is involved in the as yet unknown mechanism of action of these therapies. Indeed, animal studies have shown that antidepressants do affect deiodinase activities and T3 and T4 concentrations in rat brain. However, the effects are highly area specific and dependent on the drug administered and the time of day at which the investigation was conducted. Although the mechanism of thyroid hormone action on CSF signal transduction is as yet unknown, effects on "general CNS functions" such as second messengers, G-proteins or calcium homeostasis seem more likely than specific effects on the different receptor systems.

Animals↗
PubMed1991

[Retinal vascular occlusion in a young patient with hemostatic abnormalities].

Retinal vascular occlusion (RVO) in the young patient without vascular parietal disease have been encountered in different pathologic states, coagulopathy being frequent. We started a prospective study in Geneva to find out the hypercoagulable states responsible for RVO. We give suggestions to the paraclinical investigations to perform. We discuss the primary and secondary hypercoagulable states in the light of two patients who had coagulation abnormalities.

Adult↗
PubMed1991

[Occlusion of a cilioretinal artery associated with occlusion of the central retinal vein].

Cilioretinal artery occlusion (CLRAO) may be occasionally associated with central retinal vein occlusion (CRVO). This combined retinal vascular pathology is described in 5 patients. In this clinical setting the vulnerability of cilioretinal vessels can be explained by the difference in regulatory mechanisms between choroidal and retinal blood flow. The type of CRVO may predict whether the CLRAO is primary or secondary to the CRVO.

Adult↗
PubMed1990

Neuroendocrinological investigations during sleep deprivation in depression. I. Early morning levels of thyrotropin, TH, cortisol, prolactin, LH, FSH, estradiol, and testosterone.

Measurements of 12 hormones were conducted in patients with major depressive disorder at 8 AM on the morning before and at 8 AM on the morning after total sleep deprivation (SD). Thyrotropin (TSH), thyroxine (T4), triiodothyronine (T3), and free T3 (fT3) were measured in 50 patients, free T4 in 39 patients, reverse T3, cortisol, prolactin, luteinizing hormone, and follicle-stimulating hormone in 21, estradiol in 20 (women), and testosterone in 14 (men). After SD, there was a significant rise in TSH, T4, T3, and fT3 concentrations and a significant fall in testosterone levels. The increases in TSH levels were significantly correlated to clinical response. Responders to SD had higher T4, fT4, rT3, and testosterone concentrations before SD. Neither age, gender, polarity, nor antidepressant medication had a clearly significant effect on the response to SD.

Adult↗
PubMed1990

Neuroendocrinological investigations during sleep deprivation in depression. II. Longitudinal measurement of thyrotropin, TH, cortisol, prolactin, GH, and LH during sleep and sleep deprivation.

Thyrotropin (TSH), thyroxin (T4), triiodothyronine (T3), free T3 (fT3), cortisol, prolactin, and human growth hormone (HGH) were measured every 2 hr during a night of sleep, the following day, and a night of sleep deprivation (SD) in 14 patients with major depressive disorder. In subgroups fT4 (n = 5), reverse T3 (rT3), and luteinizing hormone (LH) (n = 6) were also investigated. Significant increases in TSH, T4, fT4, T3, fT3, rT3, and cortisol and decreases in prolactin levels occurred during the night of SD, compared to the pattern during the night of sleep. The pre-SD T4 and T3 levels of the responders to SD were already higher than in the nonresponders, and increased less during SD. The cortisol and HGH concentrations of the responders rose higher during SD than those of the nonresponders. Changes in TSH and prolactin were not correlated to clinical response. Analysis of possible neurochemical mechanisms underlying this "pattern" of changes in different endocrine profiles suggests that enhanced noradrenergic activity might play a role in the changes in TSH, cortisol, thyroid hormones, and possibly HGH secretion during SD, and increased dopaminergic tone probably induced the decline in prolactin levels. Additional effects of the serotonergic system cannot be excluded at present. In conclusion, the data suggest that enhanced noradrenergic activity of the locus coeruleus stimulates alpha and/or beta adrenergic receptors in depressed patients during SD. This mechanism could well be involved in the antidepressant effect of this therapy.

Adult↗
PubMed1990

Thyrotropin (TSH) and thyroid hormone concentrations during partial sleep deprivation in patients with major depressive disorder.

Thyrotropin (TSH), thyroxine (T4), free T4, triiodothyronine (T3), and free T3 (fT3) concentrations were measured in 25 patients with major depressive disorder at 8 a.m. both before and after partial sleep deprivation (PSD) during the second half of the night. Significant increases in TSH and T3 levels and a corresponding trend in fT3 levels were seen. No convincing correlations occurred between changes in the secretion of any of the hormones and the antidepressant effect of PSD. However, this does not rule out the possibility that the two phenomena, which occur in depression at different anatomical levels with presumably different degrees of disturbance in the respective receptor systems, have common underlying neurochemical mechanisms. Comparison of the effect of the PSD on changes in hormone secretion and mood with the corresponding effects in a sample of depressed patients who underwent total sleep deprivation showed no significant differences between the effects of these two forms of sleep deprivation on either variable.

Adult↗
PubMed1990

The influence of physical activity and posture on the antidepressant effect of sleep deprivation in depressed patients.

A possible role of the factors 'physical activity' and 'posture' in the antidepressant effect of a total night's sleep deprivation (TSD) was investigated in 30 patients with major depressive disorder. Fifteen patients underwent TSD under 'conventional' conditions, while the other 15 were kept in bed during TSD but were not permitted to sleep. There was no significant difference between the antidepressant effects of TSD in the two groups. This result suggests that it is wakefulness itself rather than changes in physical activity or posture that is involved in the mechanism of the antidepressant action of TSD.

Adult↗
PubMed1989

[Bee and wasp venom allergy].

Since allergic reactions to insect venom can become life-threatening, accurate diagnosis and proper treatment are important. The diagnosis of insect venom allergy is made on the basis of the history, a skin test taking the form of an intradermal titration series, and serodiagnosis (IgE). In proven allergy, the patient must be informed about measures to be taken to avoid being stung. Furthermore, the patient will have always to carry a "shock kit" comprising an antihistaminic, a steroid and adrenalin in the form of an aerosol. As specific therapy, desensitization is available.

Anaphylaxis↗
PubMed1989

[Epidemiologic study of 2 S. typhimurium outbreaks using plasmid fingerprints].

An outbreak of salmonellosis in an old people's home is reported. The infectious agent, S. typhi-murium, was isolated not only from several inmates but also from sick cows of the farm belonging to the home, in animal feed, from employees of the local butcher's shop, and finally in sludge from the local sewage plant. Plasmid analysis provided evidence of a common origin for the isolated S. typhi-murium strains. The incriminated strains harboured, together with two low-molecular-weight plasmids, a plasmid of approximately 50 Mdal, which was also demonstrated in some other S. typhi-murium strains isolated from clinical cases in the area around St. Gallen.

Adult↗