PubMed Health⌕ Search

Biomedical subjects

D Riemann

Publications and source records attributed to D Riemann.

At least 19 recordsLinked to original sources
PubMed1997

Circadian profiles of melatonin in melancholic depressed patients and healthy subjects in relation to cortisol secretion and sleep.

Circadian secretion of melatonin was measured in melancholic depressed patients (n = 9) and age- and sex-matched healthy control patients (n = 9). The mean age of the depressed patients was 29 years, i.e. younger than in most earlier studies, and a drug-free interval of 3 weeks preceded the investigations. Melatonin secretion was similar in depressed patients and healthy subjects with no significant differences at any of the time points, thus not confirming earlier studies in which depressed patients were found to have lower melatonin levels than control patients. The discrepancy between our result and earlier studies may be explained by different patient characteristics such as age, duration of illness, previous treatment, and alcohol intake. It is conceivable that a diminution of nocturnal melatonin secretion in depressed patients might only occur during the long-term course of the depressive illness and/or its pharmacological treatment.

Adult↗
PubMed1997

Induction of aminopeptidase N/CD13 on human lymphocytes after adhesion to fibroblast-like synoviocytes, endothelial cells, epithelial cells, and monocytes/macrophages.

Aminopeptidase N (APN/CD13) is a transmembrane ectoenzyme occurring on a wide variety of cells. In contrast to monocytes and granulocytes, lymphocytes of peripheral blood do not express CD13 Ag. However, tumor-infiltrating T cells in renal cell cancer as well as synovial fluid T cells from patients suffering from various forms of arthritis can be CD13 positive. To learn more about expression of CD13 in these tissues, we cocultured lymphocytes with different adherent cell lines. CD13 expression was induced in T and B lymphocytes upon adhesion to fibroblast-like synoviocytes, HUVEC, renal tubular epithelial cells, and monocytes/macrophages but not always upon interaction with different tumor cell lines. Induction of APN was rapid, occurring as early as 1 h after coincubation. Expression persisted for >3 days and partially resisted inhibition by cycloheximide. Fixation of adherent cells with paraformaldehyde could not prevent induction of CD13 in lymphocytes. Soluble APN from human kidneys or placenta could not induce CD13 expression on lymphocytes. Induction of CD13 Ag on lymphocytes required direct cell-to-cell contact as shown in experiments using dual chambers. Lymphocytes exhibited an induction not only in CD13 protein but also in Ala-pNA-cleaving enzyme activity and in CD13 mRNA. Lymphocytic expression of CD13 represents a potentially increased cellular ability to inactivate inflammatory mediators. Furthermore, CD13 could be involved in adhesion, in lymphocytic migration, or in the Ag processing of peptides bound in the groove of MHC class II molecules.

B-Lymphocytes↗
PubMed1997

Interleukin-6-(IL-6) plasma levels in depression and schizophrenia: comparison between the acute state and after remission.

The concentration of cytokines such as Interleukin-6 (IL-6) has been reported to be elevated in depressed and schizophrenic patients and, in healthy persons, upon stress. Interleukin-6 plasma levels were determined in depressed (n = 12) and schizophrenic (n = 32) patients during the acute state of illness and after remission at approximately 8 weeks after admission and were compared with healthy controls (n = 12). Patients were diagnosed according to DSM-III-R by the Structured Clinical Interview (SCID). Severity of illness was assessed for depression by the Montgomery Asberg Depression Rating Scale (MADRS) and for schizophrenia by the Brief Psychiatric Rating Scale (BPRS). Interleukin-6 plasma concentrations were elevated during the acute state either of depression or of schizophrenia if compared to controls. After remission, IL-6 concentrations in depressed and in schizophrenic patients had decreased and did not differ significantly from controls. We hypothesize that the elevated IL-6 levels during the acute state of depression or schizophrenia may reflect an unspecific stress response.

Acute Disease↗
PubMed1997

Periodic limb movements during sleep are a frequent finding in patients with Gilles de la Tourette's syndrome.

Gilles de la Tourette's syndrome (GTS) and restless legs syndrome (RLS) are two different neurological disorders with common features such as involuntary movements. In both disorders a disturbance of the dopaminergic system has been considered among other possible mechanisms. Since periodic leg movements (PLMS) during sleep are the predominant objective finding in RLS, the aim of this study was to investigate sleep parameters in GTS patients with particular emphasis on PLMS. Seven drug-free patients with GTS and seven age- and sex-matched healthy controls were studied polysomnographically, including superficial electromyogram (EMG) leads on all four extremities. A high number of PLMS were found in five of seven, and periodic arm movements in four of seven GTS patients. Total sleep time was significantly lower (P < 0.05) in the GTS patients than in the controls, which confirms earlier findings. The presence of PLMS in GTS might point towards evidence for a pathophysiological relationship between GTS and RLS, which, however, is not supported by the different responses to pharmacological treatments.

Adolescent↗
PubMed1997

[Psychological, psychotherapeutic and other non-pharmacologic forms of therapy in treatment of insomnia. Position of the "Insomnia" Study Group of the German Society of Sleep Research and Sleep Medicine].

Psychological and psychotherapeutic techniques are an essential part of the treatment of insomnia. Mainly two facts stress the importance of psychological/psychotherapeutical strategies for insomnia: (1) Concepts for non-drug treatment aim at improvement of the symptoms and the underlying cause of the disease and (2) disadvantages of hypnotic therapy such as substance abuse or addiction are avoided. Effective treatment techniques such as patients education and counseling, sleep hygiene, stimulus control and relaxation techniques should be known to every therapist, especially general practitioners who treat the majority of patients haring difficulties in initiating or maintaining sleep. Several other effective behavioural techniques, e.g. sleep restriction, or cognitive therapy, and psychotherapy should be used only by skilled and trained experts. Insomniacs with chronic and severe complaints should be treated by therapists with experience in sleep medicine. Multimodal treatment strategies are provided for by sleep disorder centres and combine effective treatment elements in structured therapeutic concepts. There is absolute consensus of opinion that every hypnotic treatment of an insomniac patient should be combined with basal elements of non-drug treatment strategies.

Behavior Therapy↗
PubMed1997

Phenotypic analysis of T lymphocytes isolated from non-small-cell lung cancer.

BACKGROUND: The study of the nature of tumor-infiltrating lymphocytes (TIL) may provide insight into the complex issue of tumor-host interactions. METHODS: Cytofluorometric analysis was performed to characterize the phenotypic profiles of TIL from non-small-cell lung cancers (NSCLC) and pulmonal metastases of different primary locations. An extensive panel of antibodies was used specific to different activation-associated molecules on T cells. In 10 patients, findings on the T cell phenotype of TIL were compared with the findings in peripheral blood lymphocytes (PBL) from the same patients. Furthermore, we investigated whether the measurement of the TIL phenotype might serve as a prognostic parameter correlating with survival of patients with NSCLC. RESULTS: In contrast to PBL, T cells infiltrating lung tumors expressed significantly higher amounts of various activation antigens. However, the immunophenotype of TIL hardly differed among different histological subtypes and pulmonal metastases. Addressing the prognostic value of the lymphocytic composition of TIL, we found no significant difference in the survival of NSCLC with high or low percentages of T and natural killer cells, whereas high percentages of B cells were associated with increased survival (p = 0.05). Patients with high percentages of CD13+ tumor-infiltrating T cells had significantly poorer prognosis according to Cox's multivariate analysis. CONCLUSION: Our results indicate that different tumor histologies within the lung are characterized by a 'similar' T cell phenotype, at least with respect to the surface molecules studied by us. The measurement of the expression of activation-associated markers on T cells may have prognostic value in the pathological evaluation of NSCLC.

Adult↗
PubMed1997

Sleep deprivation combined with consecutive sleep phase advance as a fast-acting therapy in depression: an open pilot trial in medicated and unmedicated patients.

OBJECTIVE: The authors' goal was to test the hypothesis that the antidepressant effect of total sleep deprivation can be maintained by initially avoiding sleep during a supposedly "critical" time period in the early morning. METHOD: They studied 33 inpatients with major depression, melancholic type, all of whom responded positively to total sleep deprivation. Twelve of the patients were men and 21 were women; their mean age was 46.7 years (SD = 13.7). After total sleep deprivation, the patients started a sleep schedule from 5:00 p.m. to 12:00 midnight, which then was shifted back by 1 hour each day until a sleep time of 11:00 p.m. to 6:00 a.m. was reached. RESULTS: Twenty (61%) of the 33 patients who responded to total sleep deprivation with an improved state of mood maintained this improvement during sleep phase advance therapy. Drug-free and medicated patients did not differ from each other. CONCLUSIONS: The rapid amelioration of mood observed with total sleep deprivation can be preserved with a succeeding phase shift of the sleep period.

Antidepressive Agents↗
PubMed1996

Treatment of fibroblast-like synoviocytes with IFN-gamma results in the down-regulation of autotaxin mRNA.

In an effort to isolate genes that change expression at the mRNA level during treatment of fibroblast-like synoviocytes (SFC) with IFN-gama, we performed a differential display analysis. Here, we report the isolation of a cDNA clone corresponding to a 3.1 kb mRNA species that is reduced in synoviocytes after culture with IFN-gama. Sequence analysis revealed the 211 bp length cDNA clone to be identical to the motility-stimulating 125 kDa protein autotaxin (ATX). The down-regulation of ATX mRNA was confirmed by Northern blot analysis as well as competitive RT-PCR. SFC express 1 ng ATX mRNA/microgram total RNA. IFN-gama down-regulated ATX mRNA up to 50% as compared to control. Our results add a new finding to the manifold functions described for IFN-gama in rheumatoid arthritis.

Base Sequence↗
PubMed1996

Effect of tetrahydroaminoacridine on sleep in healthy subjects.

The present study investigated the impact of the cholinesterase inhibitor tetrahydroaminoacridine (THA; tacrine) on sleep in healthy subjects. According to the reciprocal interaction model of non-rapid eye movement (NREM) and REM sleep regulation, which postulates a primary role in cholinergic neurotransmission for the initiation and maintenance of REM sleep, it was expected that THA would lead to an earlier onset of REM sleep. In 12 healthy subjects aged from 21 to 50 years two different doses (20 mg, 40 mg) were administered 1 hour prior to bed time and compared to placebo. Only the higher dose of THA significantly shortened REM latency. No other significant effects on sleep architecture were observed, although administration of 40 mg tacrine was associated with a decrease in sleep efficiency and a prolongation of sleep latency. Blood plasma levels of tacrine and its metabolite 1-hydroxytacrine measured prior to sleep and during the first 90 min of sleep were significantly correlated with the onset of REM sleep in relation to the timing of drug administration (only for the 20 mg dose). The reversible cholinesterase inhibitor THA exerts effects on REM latency comparable to those observed with other cholinomimetic agents.

Adult↗