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Biomedical subjects

C Mueller

Publications and source records attributed to C Mueller.

At least 19 recordsLinked to original sources

Prevention of autoimmune diabetes mellitus in NOD mice by transgenic expression of soluble tumor necrosis factor receptor p55.

The non-obese diabetic (NOD) mouse represents a relevant animal model of autoimmunity for insulin-dependent diabetes mellitus. The pathogenic role of tumor necrosis factor (TNF) in insulitis and beta cell destruction observed in these mice remains controversial, since injections of TNF or of anti-TNF antibodies have been reported to exert protection or acceleration of diabetes, depending on the timing of administration. In this study, we demonstrate that, in contrast to the non-transgenic littermates, NOD mice with permanent neutralization of TNF by high blood levels of soluble TNF receptor p55-human FcIgG3-fusion molecules resulting from the expression of a transgene are protected from spontaneous diabetes. They are also protected from accelerated forms of disease caused by transfer of NOD spleen cells or cyclophosphamide injections. This protection is associated with a marked decrease in the severity and incidence of insulitis and in the expression of the adhesion molecules MAdCAM-1 and ICAM-1 on the venules of pancreatic islets. These data suggest a central role for TNF-alpha in the mediation of insulitis and of the subsequent destruction of insulin-secreting beta-cells observed in NOD mice. They may be relevant to cell-mediated autoimmune diseases in general, in which treatment with soluble TNF receptors might be beneficial.

Animals

CD5- CD8 alpha beta intestinal intraepithelial lymphocytes (IEL) are induced to express CD5 upon antigen-specific activation: CD5- and CD5+ CD8 alpha beta IEL do not represent separate T cell lineages.

We followed alpha beta T cell receptor (TCR) usage in subsets of gut intraepithelial lymphocytes (IEL) in major histocompatibility complex class I-restricted alpha beta TCR-transgenic (tg) mice. The proportion of tg alpha beta TCR+ CD8 alpha beta IEL is reduced compared with CD8+ splenocytes of the same animal, particularly under conventional conditions of maintenance. Further fractionation of CD8 alpha beta IEL according to the expression level of surface CD5 revealed that in conventionally housed animals tg TCR+ CD5- CD8 alpha beta IEL are as frequent as in specific pathogen-free (SPF) mice, whereas tg TCR+ CD5int or, even more pronounced, tg TCR+ CD5hi CD8 alpha beta IEL are greatly diminished when compared with mice kept under SPF conditions. Upon antigen-specific stimulation of CD5- CD8 alpha beta IEL in vitro, CD5 surface expression is up-regulated on a large fraction of cells within 48 h. Up-regulation of CD5 surface expression is further enhanced by the presence of the anti-alpha IEL monoclonal antibody 2E7. This clearly demonstrates that CD5-, and CD5+ CD8 alpha beta IEL cannot be considered as separate T cell lineages.

Animals

Ocular flutter and truncal ataxia may be associated with enterovirus infection.

We report on three patients who presented a rare, uniform clinical syndrome consisting of ocular flutter and truncal ataxia. In all patients the symptoms followed an upper respiratory infection and resolved without sequelae within a few weeks. Previous reports have emphasized the apparent relationship of this entity to infectious disease, but the infectious agent remained uncertain. In one patient we could find a significant rise in antibody titres to enterovirus. We are not aware of any other similar documented case.

Adult

Cytotoxic cells are activated in cellular infiltrates of alcoholic chronic pancreatitis.

BACKGROUND & AIMS: Perforin messenger RNA (mRNA) expression has been shown to be a specific in vivo activation marker for cytotoxic cells. In this study, the contribution of cell-mediated cytotoxicity in the pathogenesis of alcoholic chronic pancreatitis is assessed. METHODS: Tissue sections of patients with alcoholic chronic pancreatitis were analyzed for perforin mRNA expression by in situ hybridization. In a further step, the phenotype and the relative frequency of perforin mRNA-expressing cells were determined. RESULTS: In the normal pancreas, perforin mRNA-expressing cells are rarely present (mean, 0.3 cells/mm2). In contrast, the frequency of perforin mRNA-expressing cells is increased severalfold in diseased tissue specimens (mean, 6.6 cells/mm2). The frequency of perforin mRNA-expressing cells is high in the CD56+ (18%) and CD8+ cell population (12%) but low in the CD4+ cell population (1%). CONCLUSIONS: The significantly elevated frequencies of perforin mRNA-expressing cells in the pancreas of patients with alcoholic chronic pancreatitis suggest an involvement of cell-mediated cytotoxicity in the pathogenesis of this disease. The preferential localization of these activated cells close to areas with parenchyma provides circumstantial evidence that autoreactive cytotoxic cells may contribute to tissue destruction in alcoholic chronic pancreatitis.

Cell Separation

The C-X-C chemokine ENA-78 is preferentially expressed in intestinal epithelium in inflammatory bowel disease.

BACKGROUND & AIMS: Secretion of chemokines by epithelial cells may represent a crucial event in the pathogenesis of inflammatory bowel disease (IBD). Expression of the chemokine epithelial neutrophil-activating peptide 78 (ENA-78) was monitored in patients with IBD and normal controls. METHODS: In situ hybridizations were performed on 41 tissue specimens from 15 patients with IBD and 10 controls to detect ENA-78 messenger RNA (mRNA). Immunofluorescence stainings were used to localize ENA-78 protein. RESULTS: Intestinal epithelial cells expressing ENA-78 mRNA at detectable levels are found at comparable frequencies in patients with Crohn's disease and ulcerative colitis. Tissue specimens with mild to moderate histological signs of disease activity show slightly higher frequencies of ENA-78 mRNA-expressing epithelial cells than areas with signs of severe disease activity (P = 0.14). Immunofluorescence stainings showed presence of the ENA-78 protein in > 90% of preserved epithelial cells in IBD, in control tissues, ENA-78 mRNA was not detectable, and ENA-78 protein was detectable in 0%-30% of epithelial cells. CONCLUSIONS: The observations are in agreement with a role of the C-X-C chemokine ENA-78 in the pathogenesis of IBD.

Acute Disease

The failure of 'adult' interventions with adolescent depression: what does it mean for theory, research and practice?

The literature on the biological and phenomenologic presentation of major depressive disorder (MDD) in adolescents is reviewed and compared with that of depressed adults. Biological and psychosocial treatment approaches with adults and adolescents are then contrasted and the applicability of adult interventions to adolescents is examined. Some biological, cognitive, and experiential differences between adult and adolescent MDD may have treatment implications which have not yet been adequately addressed in the field. No effective treatments for adolescent MDD have, as yet, been developed or empirically tested. Based upon the results of this review, suggestions are made for the direction of future research.

Adolescent

Detection of perforin and tumour necrosis factor alpha mRNA expressing cells in sclerosing lymphocytic lobulitis of the breast.

The contribution of a cellular immune response to tissue destruction in sclerosing lymphocytic lobulitis of the breast is not well understood. In this study, comparison of one case with two age matched control cases showed an increased frequency of activated perforin mRNA expressing cells at the site of tissue destruction in lobulitis. Along with the detection of tumour necrosis factor alpha (TNF alpha) mRNA expressing cells in the infiltrates, the striking association of perforin expressing activated cytotoxic cells with remaining gland parenchyma and the high level of perforin mRNA suggests activation of cytotoxic cells in situ. These findings are evidence that cell mediated cytotoxicity plays a significant role in the destruction of mammary gland tissue in sclerosing lymphocytic lobulitis.

Adult

Are aluminium potroom workers at increased risk of neurological disorders?

OBJECTIVE: To determine whether long term potroom workers in an aluminium smelter are at increased risk of neurological disorders. METHODS: Cross sectional study of 63 current and former aluminium potroom workers first employed before 1970 and with at least 10 years of service. A group of 37 cast house and carbon plant workers with similar durations of employment and starting dates in the same smelter were used as controls. The prevalence of neurological symptoms was ascertained by questionnaire. Objective tests of tremor in both upper and lower limbs, postural stability, reaction time, and vocabulary were conducted. All subjects were examined by a neurologist. RESULTS: No significant differences in age, race, or education were found between the two groups. Although the potroom group had higher prevalences for all but one of the neurological symptoms, only three odds ratios (ORs) were significantly increased; for incoordination (OR 10.6), difficulty buttoning (OR 6.2), and depression (OR 6.2). Tests of arm or hand and leg tremor in both the visible and non-visible frequencies did not show any significant differences between the two groups. Testing of postural stability showed no definitive pattern of neurologically meaningful differences between the groups. There were no significant differences between the two groups in reaction time, vocabulary score, or clinical neurological assessment. CONCLUSIONS: The objective measures of neurological function provided little support for the finding of increased neurological symptom prevalences in the potroom workers, although increased symptoms may be an indicator of early, subtle neurological changes. The results provide no firm basis for concluding that neurological effects among long term potroom workers are related to the working environment, in particular aluminium exposure, in potrooms. These findings should be treated with caution due to the low participation of former workers and the possibility of information bias in the potroom group.

Adult

Inhibition of submandibular and lacrimal gland infiltration in nonobese diabetic mice by transgenic expression of soluble TNF-receptor p55.

Besides a prominent mononuclear cell infiltration of the islets of Langerhans, nonobese diabetic (NOD) mice also show massive cellular infiltrates of the submandibular and lacrimal glands concomitant with histological signs of tissue damage. To obtain insights into the mechanisms operative during the initiation and progression of tissue damage, we followed by in situ hybridization the appearance of cells containing mRNA of the gene encoding the proinflammatory cytokine TNF-alpha in the cellular infiltrates. Cells expressing TNF-alpha are mainly located in infiltrates, are absent in nonaffected glands, and are preferentially found among CD4 T cells. Secretion of TNF-alpha by gland-infiltrating cells was confirmed by an ELISPOT procedure. Direct evidence for an instrumental role of TNF-alpha in initiation and progression of submandibular and lacrimal gland infiltration is provided by the observed significant reduction in the extent of infiltration in nonobese diabetic mice transgenic for a soluble TNF receptor p55 fused to the Fc part of human IgG3. This protection from infiltration is paralleled by decreased expression of the adhesion molecules ICAM-1 and VCAM-1 in submandibular and lacrimal glands. These data suggest a central role of TNF-alpha in the initiation and progression of autoimmune tissue destruction of salivary glands and indicate beneficial effects of soluble TNF receptors in the treatment of organ-specific autoimmune diseases.

Animals

Differential in situ expression of the genes encoding the chemokines MCP-1 and RANTES in human inflammatory bowel disease.

Two chemotactic cytokines, monocyte chemoattractant protein-1 (MCP-1) and RANTES, possibly contribute to the recruitment and activation of leukocytes in inflamed tissues. The expression of these cytokine genes was evaluated in tissue sections from resected bowel segments of 14 patients with inflammatory bowel disease (IBD) and seven control patients by use of 35S-labelled antisense RNA probes. MCP-1 and RANTES transcripts were generally increased in the intestinal mucosa of patients with IBD, compared with controls. Whereas MCP-1 gene expression in the mucosa was restricted to the lamina propria, the gene coding for RANTES was expressed in intraepithelial lymphocytes and in the subepithelial lamina propria. Furthermore, MCP-1 mRNA, but not RANTES mRNA, was abundant in vessel-associated cells, such as endothelial cells, medial smooth muscle cells, and intraluminal cells; in smooth muscle cells of the intestinal tunica muscularis; and in cells of the myenteric plexus. Compared with controls, a significant increase of MCP-1-expressing cells was observed in tissue specimens from patients with IBD, in endothelial cells of venules, and in cells present in the lumen of intestinal vessels. Conversely, the expression of MCP-1 mRNA in smooth muscle cells and myenteric plexus cells appeared to be comparable in control and diseased intestines. The increased number of MCP-1 and RANTES mRNA-expressing cells in mucosa from patients with IBD suggests that these cytokines play a role in the pathogenesis of mucosal inflammation. Furthermore, the expression of the MCP-1 gene in vessel-associated cells may indicate its involvement in mechanisms regulating the adhesion of blood monocytes to endothelial cells.

Adult

Safety of meloxicam: a global analysis of clinical trials.

Meloxicam is a new preferential cyclooxygenase-2 (COX-2) inhibitor for the treatment of rheumatic disease. This paper presents a global safety analysis of data from meloxicam clinical studies, focusing on gastrointestinal (GI) adverse events. Meloxicam 7.5 and 15 mg (n = 893 and 3282) were compared with piroxicam 20 mg (n = 906), diclofenac 100 mg slow release (n = 324) and naproxen 750-1000 mg (n = 243). With respect to all GI adverse events, meloxicam 7.5 and 15 mg were significantly better than all comparators in a pooled analysis of double-blind studies in rheumatoid arthritis (RA) and osteoarthritis (OA). When examining non-serious GI events, severe GI events, discontinuous due to GI events, dyspepsia, abdominal pain and upper GI events, both meloxicam doses were significantly better than comparator non-steroidal anti-inflammatory drugs (NSAIDs) in most cases. Where statistical significance was not demonstrated, there was generally a trend in favour of meloxicam. With respect to upper GI perforations, ulcerations and bleedings, the most serious of NSAID-associated side-effects, meloxicam was better tolerated than the comparators, reaching statistical significance for piroxicam and naproxen. Meloxicam's improved GI safety profile is likely to be due to its preferential inhibition of inducible COX-2 relative to constitutive COX-1.

Adult

Monocular elevation paresis and contralateral downgaze paresis from unilateral mesodiencephalic infarction.

A 26 year old woman presented with monocular elevation paresis of the right eye, contralateral paresis of downward gaze, and subtle bilateral ptosis. Magnetic resonance imaging disclosed a unilateral embolic infarction restricted to the mesodiencephalic junction involving the left paramedian thalamus. Preserved vertical oculocephalic movements and intact Bell's phenomenon suggested a supranuclear lesion. This rare "crossed vertical gaze paresis" results from a lesion near the oculomotor nucleus affecting ipsilateral downward gaze and contralateral upward gaze fibres, originating in the rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF).

Adult

Monocyte chemoattractant protein-1 gene expression in prostatic hyperplasia and prostate adenocarcinoma.

Human monocyte chemoattractant protein-1 (MCP-1) has been shown to act as a chemokine in the recruitment of monocyte/macrophages during inflammation states. Furthermore, there is increasing evidence that MCP-1 is involved in the recruitment of tumor-associated macrophages. In vivo, one of the major cellular sources of MCP-1 are the smooth muscle cells. As MCP-1 gene expression and/or protein production in these cells is not necessarily correlated with the accumulation of inflammatory cells, there might possibly be additional functions of this cytokine. In the present study, we investigated by use of 35S-labeled antisense RNA probes whether the MCP-1 gene is expressed in tissue specimens of benign prostatic hyperplasia (n = 13) and specimens of prostate carcinoma (n = 8), both of which are characterized by a prominent fibromuscular stroma and inconspicuous inflammatory infiltrates. MCP-1 transcripts were located in stromal smooth muscle cells and, additionally, in basal cells of benign prostatic glands. In prostate carcinoma, the number of MCP-1 mRNA-expressing cells was significantly less than in benign prostatic hyperplasia. MCP-1 transcripts were located in preserved fibromuscular stroma and in basal cells of entrapped non-neoplastic glands but not in carcinomatous cells. Immunohistochemical staining with polyclonal antibodies raised against MCP-1 revealed strong reactivity in the fibromuscular stroma surrounding both benign and malignant glands. MCP-1 gene expression or immunoreactivity for anti-MCP-1 antibodies was not related to the rare, lymphocytic interstitial infiltrates. The results show that 1) in the absence of significant leukocyte accumulation, it is unlikely that MCP-1 exerts chemotactic functions in the prostate and 2) that MCP-1, in contrast to previous findings in a wide variety of other human neoplasms, is not expressed in carcinomatous cells of the prostate.

Adenocarcinoma

[Spontaneous and visually-induced oculomotor reactions in microgravity (Results of Austrian-Russian Experiment "Optovert" performed within the frame of program "Austromir", part II)].

Results of investigation of spontaneous and induced by vertical linear and sinusoid optokinetic stimulation oculomotor reactions in short- and long-term space missions are reported. Adaptation to microgravity was shown to be associated with rearrangement in sensory interactions even on a background of good subjective well-being and absence of abnormal autonomous nervous reactions. In the early period of adaptation to microgravity records were made of modified spontaneous oculomotor activity (spontaneous vertical nystagmus) and vertical optokinetic nystagmus (VOKN) including alterations in amplitude and VOKN amplification coefficient.

Adaptation, Ocular

The detection of 6-monoacetylmorphine in urine, serum and hair by GC/MS and RIA.

6-Monoacetylmorphine (6-MAM) is a good indicator for the intake of heroin and can be detected in blood, urine and hair of heroin users. A new radioimmunoassay (RIA) designed specifically for 6-monoacetylmorphine (6-MAM) was tested for its usefulness for the quantitation of the drug in urine, serum and hair. Its cross-reactivity with heroin and its metabolites, and related compounds was also determined. Eighty-nine hair, six serum and 25 urine samples where 6-MAM had been previously identified by GC/MS were analysed for 6-MAM with the new RIA kit. A good correlation existed between the GC/MS and RIA results for the hair samples. However, the amount of 6-MAM found in serum and urine differed considerably between the two methods. This difference could be explained by the cross-reactivity of the antibody with morphine and morphine-6-glucuronide, which are present in much larger amounts in serum and urine, than in hair. To evaluate a new rationalisation procedure, some hair samples were split into two portions after incubation. One part was analyzed for 6-MAM by RIA, and the other portion by GC/MS.

Cross Reactions

Detection of transcripts and binding sites for colony-stimulating factor-1 during bone development.

Colony-stimulating factor-1 (CSF-1), originally characterized as the growth factor for the cells of the mononuclear phagocytic system, has been shown to be essential for osteoclast formation. The aim of the present study was twofold: (i) to investigate the expression of transcripts encoding CSF-1; and (ii) to detect binding sites for CSF-1 during bone development. As a model, metatarsal rudiments from embryonic mice of different ages were used, an in vivo system allowing one to follow osteoclast formation. In 16-day-old embryos, proliferating osteoclast precursors are located on the outer surface of the rudiments. They differentiate subsequently to post-mitotic precursors. At 18 days, the precursors fuse and the mature osteoclasts invade the mineralized cartilage of the rudiments to excavate the future bone marrow cavity. Within this study, in situ hybridization on sections of whole paws from 17-day-old embryos revealed CSF-1 transcripts to be present in cells lining the outside of the midregion of the metatarsals. One day later, cells containing CSF-1 mRNA were found within the mineralized cartilage. The levels of transcripts encoding CSF-1 were further increased in the bone rudiments of newborn animals. Binding sites for CSF-1 on cells in close proximity of the metatarsals were detected at embryonic age 17 days, but not before. At this stage, cells binding CSF-1 were located on the periosteum of the midregion of the metatarsal rudiment. At 18 days, cells expressing high levels of CSF-1 binding sites had invaded the mineralized cartilage.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals