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Biomedical subjects

D Riemann

Publications and source records attributed to D Riemann.

At least 73 records · Page 4Linked to original sources
PubMed1998

Regulation by transforming growth factor-beta1 of class II mRNA and protein expression in fibroblast-like synoviocytes from patients with rheumatoid arthritis.

Transforming growth factor (TGF)-beta1 is an immunosuppressive cytokine that modulates the expression of class II histocompatibility antigens on human cells. Aberrant HLA class II expression on synovial lining cells of rheumatoid arthritis synovial membrane has been described, and the extent and intensity of class II expression on the cells was claimed to be linked with the severity of the disease. In this study, the effects of TGF-beta1 on HLA class II antigen expression in fibroblast-like synoviocytes (SFC) from rheumatoid synovectomy tissues were determined by flow cytometric analysis and quantitative RT-PCR. We found that pre-incubation of cells with TGF-beta1 was able to down-regulate IFN-gamma-induced DR protein expression in SFC. TGF-beta1, additionally, down-regulated IFN-gamma-stimulated class II transactivator (CIITA) and DRB mRNA expression. The constitutive expression of CIITA mRNA was completely abolished and the constitutive expression of DRB mRNA was decreased after treatment of SFC with TGF-beta1 for 24 h. Addition of the TGF-beta inhibitor decorin to SFC for 24 h before TGF-beta1/IFN-gamma treatment was able to reduce the down-regulatory effect of TGF-beta1 on DR antigen expression induced by IFN-gamma. Using competitive RT-PCR, we found that SFC constitutively expressed decorin mRNA and that treatment of cells with TGF-beta1 for 24 h reduced the constitutive expression of decorin mRNA by 65%. Our results show that TGF-beta1 is able to reduce the expression of HLA class II mRNA and protein, and suggest a tight regulation between TGF-beta1 and decorin in SFC of the rheumatoid synovium.

Arthritis, Rheumatoid↗
PubMed1998

Endopeptidase 24.11/CD10 is down-regulated in renal cell cancer.

The regulatory mechanisms responsible for malignant transformation, tumor progression and metastasis in renal cell cancer (RCC) are still unclear, but there is some evidence that biologically active peptides might have regulatory effects on the behavior of this malignancy. Tumor cells can change local concentrations of active peptides by modulating their cell-surface enzymes. Using immunohistochemistry and enzyme-histochemistry, the expression of various membrane peptidases was examined in RCC and adjacent noninvaded renal parenchyma (n = 44). We describe the down-regulation of neutral endopeptidase 24.11 (NEP) protein expression in RCC of the clear cell/chromophilic type when compared with renal parenchyma, and show for the first time the lack of enzyme activity of NEP in RCC. The strongest expression could be found for dipeptidyl peptidase IV (DPIV) which is only decreased in RCC of the chromophobe cell type and is even present in oncocytoma. Aminopeptidase N (APN) and aminopeptidase A (APA) show attenuated expression in up to one third of clear cell/ chromophilic RCC. Chromophobe RCC and oncocytomas do not express APN, APA, NEP and gamma-glutamyltranspeptidase.

Adenoma, Oxyphilic↗
PubMed1998

Sleep and the cholinergic rem sleep induction test in patients with primary alcoholism.

Sleep disturbances of alcoholics while actively drinking and at the beginning of, and during, abstinence were frequently reported. Recently, Gillin et al. (1994) showed that a high "REM sleep pressure" at the time of admission to a 1-month inpatient alcohol treatment program predicted the relapse in nondepressed patients with primary alcoholism at 3 months following hospital discharge. We investigated 24 patients with primary alcoholism after 2-3 weeks abstinence in the sleep laboratory; in 15 of these patients the cholinergic REM sleep induction test (CRIT) with 10 mg galanthamine was performed additionally. In comparison with an age- and sex-matched healthy control group, patients had a heightened "REM sleep pressure" including shortened REM latency and increased REM density. A decrease of serotonergic neurotransmission is proposed as being the neurochemical mechanism to explain the results in alcoholic subjects. Follow-up investigations will clarify whether the sleep abnormalities in alcoholism are state- or trait-markers and whether they are suitable to predict the relapse risk.

Adult↗
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

Constitutive expression of HLA class II mRNA in synovial fibroblast-like cells from patients with rheumatoid arthritis .

We describe the quantification of the absolute amounts of HLA class II mRNA and class II transactivator (CIITA) mRNA by competitive reverse transcription polymerase chain reaction in cultured synovial fibroblast-like cells (SFC) of patients with rheumatoid arthritis. High basal levels of transcription of class II mRNA (10(7)-10(9) molecules/microgram total RNA) and CIITA mRNA were detected in cultured SFC, with DPB < DRB = DQB, although SFC only express small amounts of MHC class II proteins. In contrast to SFC, we did not detect class II mRNA nor CIITA mRNA in skin fibroblasts. After treatment with IFN-gamma, we observed a 3- to 28-fold increase in class II mRNA in SFC and an increase of DRB and DPB in skin fibroblasts from undetectable levels to 10(8)-10(9) molecules/microgram total RNA.

Arthritis, Rheumatoid↗
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↗