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Biomedical subjects

G Laux

Publications and source records attributed to G Laux.

At least 109 records · Page 6Linked to original sources

Growth hormone (GH) responses to GH-releasing hormone in depression: correlation with GH release following clonidine.

Twenty subjects (10 patients with major depressive disorder and 10 controls matched for age, gender, and ovarian status) received 1 microgram/kg synthetic human growth hormone-releasing hormone (GHRH)-44 amide as an i.v. bolus dose. Compared to controls, depressed patients showed a significant attenuation of net growth hormone (GH) responses to GHRH associated with normal basal GH concentrations. The blunted GH responses occurred in the face of significantly higher somatomedin C (Sm-C) concentrations. Comparison of GH responses after GHRH with GH output following the alpha 2-agonist clonidine (CLON) revealed a significant positive correlation. The concordance between GH responses after specific challenges at different levels of the GHRH-GH-somatomedin axis indicates the integrity of the hypothalamic-pituitary-somatotropic system in depression and supports the view that altered GH secretory patterns in depression may primarily be due to a suprapituitary disturbance.

Adult↗

Corticotropin and cortisol response to human CRH as a probe for HPA system integrity in major depressive disorder.

To explore the integrity of the hypothalamic-pituitary-adrenal (HPA) system in major depressive disorder, 12 patients and normal controls matched for sex, age, and body weight received 100 micrograms synthetic human corticotropin-releasing hormone (hCRH) as an i.v. bolus dose. Compared to controls, depressed patients showed an elevation in baseline cortisol and a significant attenuation of net adrenocorticotropin (ACTH) responses, while cortisol secretion in response to hCRH was normal. These abnormalities in HPA axis function and apparent discordances in the interrelationships of ACTH and cortisol baseline and net stimulation responses between depressed patients and normal controls indicate, at least in part, a derangement of the glucocorticoid-dependent negative feedback circuitry and support the hypothesis that HPA hyperactivity in depression involves neurotransmitter-mediated hypothalamic hypersecretion of CRH.

Adolescent↗

Growth hormone (GH) and prolactin responses after GH-releasing hormone in major depressive disorder: relationship to somatomedin C levels and dexamethasone suppressibility of cortisol.

To explore the growth hormone-releasing hormone (GHRH)-GH-somatomedin axis in major depressive disorder, 12 patients and 12 normal controls matched to the patients on age, sex, ovarian status and body weight received synthetic human GHRH-44 amide (1 microgram/kg) as an intravenous bolus. Compared to controls, the depressed patients showed a reduction in baseline plasma GH and a significant attenuation of net plasma GH responses to GHRH. The blunted GH responses occurred along with significantly increased somatomedin C (Sm-C) concentrations. The impairment of GH responses to GHRH and the increased Sm-C concentrations in patients with depression could have resulted from episodic hypersecretion of GH during the daytime, indicating integrity of the negative feedback circuitry. Normal feedback regulation suggests that diurnal episodic hypersecretion of GH reflects an abnormality at or above the level of the hypothalamus, so that the GHRH-GH-somatomedin axis hyperactivity observed in certain patients with major depressive disorder may be due, at least in part, to hypersecretion of hypothalamic GHRH. Our failure to demonstrate a difference in plasma prolactin (PRL) responses to GHRH between controls and depressed patients indicates that GHRH is not a PRL releaser in patients with major depression and that the altered GH secretory dynamics may not be directly related to the altered circadian PRL secretion linked to depression.

Adult↗

Antidepressant combination therapy of endogenous depressions with benzodiazepines or neuroleptics--a study comparing adjuvant treatment with oxazolam versus chlorprothixene.

Antidepressants are routinely administered in combination with benzodiazepine tranquilizers or low-potency neuroleptics. A controlled study was conducted involving 40 endogenous depressive inpatients who were treated with maprotiline in combination with the benzodiazepine oxazolam or the neuroleptic chlorprothixene. After a period of two weeks there was no significant difference in the clinical ratings (HRSD, Bf-S, BL, CGI) of the two groups studied. Only in the factor "anxiety" and the adjective mood scale scores was there a tendency toward quicker onset of action (third day) in the patient group treated with oxazolam, though it was not statistically significant. The clinical global evaluation (efficacy, tolerability) showed more favorable ratings for oxazolam than for chlorprothixene. Both substances were generally tolerated well; oxazolam hardly ever caused any side effects. However, a slight deterioration of some patients' conditions was observed after discontinuation of oxazolam.

Adult↗

Psychotropic effects of corticotropin-releasing hormone stimulation in depressive patients.

Synthetic human corticotropin-releasing hormone (hCRH) was administered as an intravenous bolus (100 micrograms) to 13 patients suffering from endogenous depression and to 12 healthy volunteers. Compared with controls, depressed patients showed a significant amelioration of mood and well-being 2 h after hCRH administration in the rating scales applied ('Befindlichkeits-Skala', 'Eigenschaftswörterliste', 'Kurzskala Stimmung-Aktivierung', Self-Rating Depression Scale, Hamilton Rating Scale for Depression). Based on our preliminary data, a psychotropic effect and at least a mediating function of hCRH regarding pathophysiology and etiopathogenesis of endogenous depressions must be assumed.

Adult↗

[Schizophrenic psychosis in a patient with Gilles de la Tourette syndrome].

A 36 year-old female patient with schizophrenia and Tourette syndrome is described. Clinical course, present neurological and psychopathological state, results of psychological testing, computed tomography and MR tomography of the skull, EEG and evoked potentials are reported. Results of neurochemical analysis of CSF and plasma are presented. Possible relationships between Tourette syndrome and schizophrenia are discussed with particular reference to neurochemical findings.

Adult↗

New type B isolates of Epstein-Barr virus from Burkitt's lymphoma and from normal individuals in endemic areas.

All Epstein-Barr virus (EBV) isolates can be classified as type A or type B depending upon the identity of their EBV nuclear antigen (EBNA) 2 protein. The great majority of isolates examined to date encode an EBNA 2A protein like that of the reference type A strain B95-8. Type B virus strains, encoding an antigenically distinct EBNA 2B protein, have as yet only been rescued from rare Burkitt's lymphoma (BL) cell lines of African origin (Jijoye, AG876). Our recent finding that type B isolates are less efficient than type A in in vitro transformation assays prompted us to determine (i) the relative contribution the two types of virus make to the incidence of BL in endemic areas of Africa (Kenya) and New Guinea and (ii) the relative incidence of infection with these two types in the normal population in these same areas. On the first point, EBNA 2 gene typing using specific DNA probes showed that four of ten recently established Kenyan BL cell lines and two of four BL cell lines from New Guinea carried type B virus isolates. To address the second point, spontaneous lymphoblastoid cell lines were established from the blood of normal virus carriers and typed for EBNA 2 at the protein level; a significant proportion (greater than 20%) of the normal population in both the above BL-endemic areas were infected with type B isolates. This is the first indication of the widespread nature of type B virus infection in any community and the first isolation of such viruses from a non-BL source. The reproducible size of the EBNA 2B protein encoded by all type B isolates irrespective of their geographical origin, and of the EBNA 1 protein encoded by all type B isolates from one area, contrasted markedly with the extreme variability in the size both of EBNA 2A and of EBNA 1 seen generally among type A isolates. This suggests that the number of type B virus strains in existence worldwide could be quite limited. Most importantly, the data suggest that type B viruses, despite their relatively poor performance in in vitro transformation assays, can contribute at least as efficiently as can type A viruses to the pathogenesis of BL.

Antigens, Viral↗

Long-term use of benzodiazepines in psychiatric inpatients.

During the past few years the problem of over-prescribing benzodiazepines has been increasingly discussed. However, up to now exact data on the extent of an abuse of these substances are relatively scarce and controversial. An analysis done at the Psychiatric State Hospital Weinsburg from 1974 to 1983 regarding the frequency of the diagnosis "Benzodiazepine-dependence" showed that in only 150 cases (0.5%) out of almost 33,000 admitted patients was the diagnosis benzodiazepine-abuse justified, with an increase since the year 1980. During a prospective study of the quarterly incidence in 1984, 18.5% of the patients admitted met the criterion of long-term use of benzodiazepines (continuous use for more than 3 months). Sociodemographic and clinical data are presented and an index of abuse/dependence is proposed.

Adult↗

Target sequences for cis-acting regulation within the dual promoter of the human c-myc gene.

Recombinant plasmids of the human c-myc promoter-leader region and the bacterial chloramphenicol acetyltransferase (cat) gene were constructed. After transfection into different rodent and human cells, the 862-base-pair (bp) PvuII fragment carrying both c-myc promoters and 350 bp of the untranslated leader conferred 1/15 to 1/30 of the CAT activity mediated by the simian virus 40 promoter. The presence of additional sequences upstream of the PvuII fragment had an overall negative effect on c-myc promoter activity detectable by titration analysis with small amounts of transfected plasmid DNA. The analysis of numerous deletion constructs in the c-myc promoter-leader region as well as S1 mapping experiments demonstrated that the high CAT activity depended largely on the presence of the second promoter. By cotransfection of c-myc-cat constructs with plasmids carrying different parts of the c-myc promoter locus, targets for positively acting cellular factors were identified. Two positive regulatory elements were mapped within the 862-bp PvuII fragment. One was localized within the 248-bp PvuII-SmaI fragment -101 to -349 bp upstream of the first cap site and the other within the 142-pb XhoI-NaeI fragment of the first exon, comprising positions -95 to +47 relative to the second cap site. We conclude that the dual promotor of the human c-myc gene represents a strong eucaryotic promotor regulated by cooperation of positively and negatively acting cellular transcription factors.

Acetyltransferases↗