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R Baumann

Publications and source records attributed to R Baumann.

At least 19 recordsLinked to original sources
PubMed2026

Anatomical location defines distinct molecular subtypes of mucosal melanoma.

BACKGROUND: Mucosal melanoma (MM) is a rare and aggressive melanoma subtype that is understudied. The relationships between anatomical location, genomic alterations, stage at presentation, and survival remain incompletely characterized. METHODS: We carried out a retrospective single tertiary center study of 105 patients with histologically confirmed MM diagnosed between 1996 and 2025. Clinical and genomic data were analyzed to evaluate associations between anatomical location, mutational profile, stage at presentation, and survival outcomes, including melanoma-specific mortality. RESULTS: Lower-body tumors arising in the anus or genital areas were enriched for KIT and splicing factor 3 subunit B1 alterations, whereas NRAS mutations were distributed across anatomical regions. Among the two most common mutated genes, NRAS-mutant tumors were more likely than KIT-mutant tumors to present with metastatic disease [53% versus 19%; P = 0.046, odds ratio (OR) 4.7, 95% confidence interval (CI) 1.15-19.41]. Lower-body tumors were associated with worse overall survival (OS) than upper-body tumors (median 2.81 versus 8.40 years; OR = 0.05) and with higher melanoma-specific mortality. In multivariable analyses, upper-body location remained independently associated with improved OS (hazard ratio 0.14, 95% CI 0.05-0.36, P < 0.001). CONCLUSIONS: Anatomical location of MMs and genomic alterations define biologically and clinically distinct subtypes.

KIT mutation↗
PubMed2006

Videocapsule endoscopy is useful for the diagnosis of intestinal lymphangiectasia.

We study two authentic cases of protein-losing enteropathy, the diagnosis of which was facilitated using Given M2A videocapsule endoscopy. The first case corresponded to a primary intestinal lymphangiectasia confirmed by jejunum biopsies and the second one to a protein-losing enteropathy with lymphatic abnormalities secondary to a chronic constrictive pericarditis. In the first case, the mucosa of jejunum presented with a diffuse oedematous aspect, whitish villi, white curved lines probably related to submucosal dilated lymphatics and lacteal juice. In the second case, capsule endoscopy showed oedematous aspect of jejunum mucosa associated with white curved lines similar to those observed in the first case. Videocapsule endoscopy is useful in cases of protein-losing enteropathy to identify presence of intestinal lymphangiectasia and to specify their localisation after ruling out other disorders liable to induce protein-losing gastrointestinal syndrome.

Adult↗
PubMed2006

Changes in leucocyte and lymphocyte subsets during tuberculosis treatment; prominence of CD3dimCD56+ natural killer T cells in fast treatment responders.

The immune responses against pulmonary tuberculosis are still poorly defined. This study describes changes in leucocyte and lymphocyte subsets during treatment to find reliable immunological markers for the disease and treatment response. Flow cytometric peripheral blood immune phenotyping, routine haematology and sputum microbiology were performed on 21 HIV-negative adult tuberculosis (TB) patients with positive sputum cultures during therapy in comparison with 14 healthy purified protein derivative (PPD)-positive volunteers. Patients at diagnosis showed high absolute neutrophil and monocyte counts which fell during treatment but low lymphocyte subset counts which increased [except natural killer (NK) and NK T cells]. High counts of a population of CD3(dim)/CD56+ NK T cells at diagnosis correlated significantly with negative sputum culture after 8 weeks of treatment. A multivariate classification technique showed improved correlation when NK cells were taken into account. In conclusion, peripheral blood white cell counts change significantly during treatment and counts at diagnosis, especially CD3(dim)/CD56+ NK T cells, hold promise in predictive models of TB treatment response.

Adolescent↗
PubMed2006

Evaluation of clinical parameters and estrogen receptor alpha gene polymorphisms for patients with endometriosis.

Endometriosis is a chronic inflammatory disease, which is especially found in women with subfertility problems with an incidence of up to 30%. The disease is considered an estrogen-dependent disorder, where DNA polymorphisms of the estrogen receptor alpha (ERalpha) in connection with endometriosis are controversially discussed. From a German population of women, clinical data associated with the disease, including the American Fertility Society (AFS) I-IV classification, and non-clinical parameters were evaluated statistically in endometriosis patients (n = 98) and in control women (n = 98) without endometriosis. Using a multivariate statistical analysis, significant associations of endometriosis with dysmenorrhea (P < 0.001) and allergies against medicaments (P = 0.042) were found. A positive trend between first grade family history of endometriosis and allergies against medicaments was also observed, suggesting a genetic relationship. From both collectives, DNA from peripheral blood was analyzed for the frequency of the ERalpha DNA polymorphisms Xba1 (A/G) and PvuII (T/C) in intron 1 and the ERalpha exonic DNA polymorphism (G229A) with an amino acid exchange (Gly77Ser) in the transactivation domain. DNA samples from endometriosis lesions and control tissues from the same collectives were also analyzed for the exonic G229A polymorphism. Only homozygote wild-type alleles for the polymorphism G229A were found, making it a rare polymorphism in mid-European individuals. Allele types for the PvuII and Xba1 polymorphisms were analyzed with the observed statistically significant clinical parameters and showed no significant association with endometriosis; however a trend with AFS IV was noted, which could contribute to lesion severity. In conclusion, the analyzed polymorphisms in the ERalpha do not have a functional role concerning specific clinical parameters associated with endometriosis.

Adolescent↗
PubMed2005

Immune activation and nutritional status in adult Crohn's disease patients.

BACKGROUND: Recent attention focused on the effect of inflammatory cytokines on intermediary metabolism contributing to the nutritional disturbances observed in acute or chronic inflammatory diseases. AIMS: To examine the interactions between immune activation and nutritional parameters in adult Crohn's disease patients. PATIENTS AND METHODS: We analysed anthropometric and biochemical nutritional parameters in 40 Crohn's disease patients and 26 healthy controls, and related them to inflammatory and immune markers. RESULTS: Weight, body mass index, mid-arm circumference, triceps skinfold thickness, as well as albumin, transthyretin, retinol binding protein, insulin growth factor-I and Vitamin A were significantly decreased in Crohn's disease patients and negatively correlated to disease activity. By contrast, erythrocyte sedimentation rate, fibrinogen, C-reactive protein, alpha1-acylglycoprotein, soluble receptor of interleukin-2, blood neopterin, tumour necrosis factor-alpha and interleukin-1beta concentrations were significantly higher in patients and positively correlated to disease activity. Nutritional parameters and acute phase reactants were linked to tumour necrosis factor-alpha and interleukin-1beta concentrations, and markers of nutritional status were negatively correlated to positive acute phase reactants. CONCLUSIONS: In Crohn's disease, inflammatory cytokines appear partly responsible for decreased nutritional status. Thus, nutritional intervention to correct nutritional (in particular protein) depletion, and/or therapeutic intervention reducing inflammation and therefore restoring adequate nutritional proteins synthesis, appears a major therapeutic goal in active Crohn's disease.

Adult↗
PubMed2005

Efficacy and safety of an olive oil-based intravenous fat emulsion in adult patients on home parenteral nutrition.

BACKGROUND: The most frequently used intravenous lipid emulsions are composed of 100% long chain triacylglycerols from soybean oil or of 50% long chain triacylglycerols-50% medium chain triacylglycerols. A newer emulsion, ClinOleic 20% containing 80% olive oil and 20% soybean oil, was suggested to reduce lipid peroxidation and immune function impairment. AIM: To assess ClinOleic 20%'s efficacy, safety and effect upon systemic inflammatory parameters in adults on home parenteral nutrition. METHODS: In stable home parenteral nutrition patients, the initial intravenous lipid emulsion was changed for ClinOleic 20%. Nutritional status, clinical and biological tolerance, and systemic inflammatory markers were analysed before and after 1 and 3 months of home parenteral nutrition, with ClinOleic 20% as intravenous lipid emulsion. RESULTS: Clinical and biological nutritional markers and inflammatory parameters did not differ between day 0 and month +3. There was no essential fatty acids deficiency. No side-effects were reported. Three of five patients presenting with migraine during home parenteral nutrition infusion at day 0 felt consistently better at month +3. CONCLUSIONS: ClinOleic 20% is safe and efficient in adult home parenteral nutrition. It maintains normal essential fatty acids status and did not influence inflammatory parameters. In contrast to studies in preterm infants or paediatric patients, no effect on vitamin E concentration or lipid peroxidation was observed.

Adult↗
PubMed2005

[Development of a new test for speech audiometry in children and results in CI children].

BACKGROUND: Speech audiometry plays an important role for hearing evaluation in children. Hearing impaired children, such as those with cochlear implant (CI) who frequently undergo testing, learn the test words by heart. Furthermore, the standard tests use words of former time. PATIENTS AND METHODS: Using the most frequently words of modern children's literature a speech assessment test was developed for children between 1 to 8 years. The material was first evaluated on normal hearing children. In a second step the phoneme and word perception scores of 35 CI children were measured using 60 - 100 dB SPL according to the most comfortable level (MCL) in free sound field. RESULTS: The performance-intensity function for the single words were highly comparable with those of the Freiburger or Göttinger speech perception test. The average speech reception threshold in CI children was 44 % (test I), 36 % (test II), 63 % (test III) and 69 % (test IV), respectively. Compared to the Mainzer and Göttinger speech perception test the new words were more difficult to understand than those of the known tests. However, a statistically significant difference could be noted only for test II. CONCLUSIONS: The new developed "Würzburger speech perception test" appears to be a useful additional tool for the evaluation of hearing impaired children in addition to the standard test procedures.

Audiometry, Speech↗
PubMed2005

Erythropoiesis and red cell function in vertebrate embryos.

All vertebrate embryos produce a specific erythroid cell population--primitive erythrocytes--early in development. These cells are characterized by expression of the specific embryonic haemoglobins. Many aspects of primitive erythropoiesis and the physiological function of primitive red cells are still enigmatic. Nevertheless, recent years have seen intensive efforts to characterize in greater detail the molecular events underlying the initiation of erythropoiesis in vertebrate embryos. Several key genes have been identified that are necessary for primitive and the subsequent definitive erythropoiesis, which differs in several aspect from primitive erythropoiesis. This review gives in its first part a short overview dealing with comparative aspects of primitive and early definitive erythropoiesis in higher and lower vertebrates and in the second part we discuss the physiological function of primitive red cells based mainly on results from mammalian and avian embryos.

Amphibians↗
PubMed2005

Neurons in monkey visual cortex detect lines defined by coherent motion of dots.

Form perception from coherent motion is an important aspect of vision. Representations of one-, two- and three-dimensional forms have been found at various stages of cortical processing using random-dot stimuli, whereas representations of biological objects like a walking human being concentrate at higher stages of processing. The perception of biological objects can be induced by sparse dot stimuli that consist of a few dots that mark the joints of the human body [G. Johansson (1973) Percept. Psychophys., 14, 201-211]. In the present study, we aimed to investigate whether neurons in early visual areas that respond to bars and edges defined by luminance contrast also signal bar-like objects from sparse dot stimuli. We studied single neurons with rows of 3-24 dots that were either collinear or scattered within a rectangular form. These dots were moved coherently on a uniform or dotted background, and human observers perceived them as rigid rods or other bar-like objects. We found neurons in the visual cortex of the awake, behaving monkey that responded to these stimuli and were sensitive to the orientation of these objects as for conventional bars or edges. Stimulus conditions that failed to induce these percepts in human observers also evoked weaker responses or none in these neurons. We found these neurons with increasing frequency in areas V1, V2 and V3/V3A. The results suggest that the visual cortex not only detects biological objects, but also lines and other bar-like objects from sparse dot stimuli, and that this function evolves at an early stage of processing.

Animals↗
PubMed2002

Catheter-related infection in patients on home parenteral nutrition: results of a prospective survey.

BACKGROUND & AIMS: Central venous catheter (CVC) infection is the most frequent complication during home parenteral nutrition (HPN). We prospectively assessed incidence and catheter-related sepsis (CRS)-associated factors in the 42 adult patients enrolled in our HPN centre since its opening. METHODS: Age, frequency of infusions, CVC type, autonomy or nurse/family aid, underlying disease, involved infectious organism(s), hospital stay, efficacy of antibiotic-lock and other infectious complications, were studied. RESULTS: CRS occurred 39 times (3/1000 days of HPN). In 37/39 cases, it was proven by both peripheral and central blood cultures. In 56% of patients, clinical signs were discrete, delaying diagnosis. Individual factors like learning potency, underlying disease (especially chronic intestinal obstruction with bacterial overgrowth), and length of remaining colon and small intestine, were slightly associated with higher CRS incidence. Usually, one organism (S. epidermidis; 51%) was detected. A total of 14 CVC were immediately removed. In the others, antibiotic-lock was more effective in patients having tunnelled catheters (TC, 50%) than implanted devices (25%; P<0.05). Mean hospital stay was 22+/-15 days, which was influenced by 3 patients presenting associated osteomyelitis. CONCLUSIONS: CRS incidence was 3/1000 days of HPN. Clinical symptoms were often discrete, suggesting importance of rigorous survey. Individual apprenticeship and risk for higher bacterial translocation seem associated to higher CRS incidence. CVC sterilization was more frequent in patients with TC.

Bacterial Infections↗
PubMed2001

Identification of an invasive, N-cadherin-expressing epithelial cell type in endometriosis using a new cell culture model.

Studies of molecular, cellular, and pathophysiological parameters in endometriosis are primarily hampered by a lack of in vitro model systems, such as endometriotic cell lines. To overcome this we successfully established cell lines from peritoneal endometriotic biopsies and characterized them at the molecular and cellular level. Two types of cells could be transformed: one exhibiting stromal cell features (cytokeratin/E-cadherin-negative), the other epithelial-like (cytokeratin-positive/E-cadherin-negative, invasive in vitro). Using a Matrigel assay the epithelial-like cell lines proved as invasive as metastatic carcinoma cells, possibly through the influence of N-cadherin implicated as a path-finding cadherin allowing cellular invasion and migration in both normal and pathophysiological processes. Our results support the idea that endometriosis, although not neoplastic, shares features with malignant cells and that metastasis in endometriosis may include mechanisms proposed for micrometastasis in cancer. Thus our cell lines will not only be useful tools for analyzing molecular and cellular events relating to endometriosis, but may also represent a paradigm for invasion and metastasis in general.

Biocompatible Materials↗
PubMed2001

Persistent inflammation and immune activation contribute to cholestasis in patients receiving home parenteral nutrition.

Liver disease is frequent in patients taking home parenteral nutrition (HPN), but its cause remains unclear. Ongoing inflammation was implicated in HPN-associated cholestasis, so we examined the relation between liver-enzyme concentrations and circulating inflammatory and immune markers in these patients. In 17 HPN patients and 10 age- and sex-matched control subjects, we examined erythrocyte sedimentation rate, blood neopterin, soluble interleukin (IL)--2 receptors, circulating tumor necrosis factor-alpha, IL-6, aspartate and alanine aminotransferases, alkaline phosphatases, and gamma-glutamyltranspeptidase (GGT) concentrations. Fourteen of 17 patients had abnormal liver function tests with an increase in alkaline phosphatases (P < 0.001), gamma-glutamyltranspeptidase (P < 0.01), and aspartate aminotransferase (P < 0.01). Alkaline phosphatases were positively correlated to erythrocyte sedimentation rate, neopterin, tumor necrosis factor-alpha, and IL-6. gamma-Glutamyltranspeptidase was positively linked to tumor necrosis factor-alpha and soluble IL-2 receptors. There was no link between aminotransferases and inflammatory parameters. Liver-enzyme concentrations were correlated to the amount of total intravenous calories and calories originating from carbohydrates but not to infused lipids (median infused lipids x kg(-1) body weight x d(-1) = 0.62 g) in contrast to recently published data. Our results confirmed that the number of infused calories contributes to liver toxicity in HPN patients and strongly suggested that sustained inflammation is probably a key factor in worsening HPN-associated cholestasis.

Adult↗
PubMed2001

Erythroid carbonic anhydrase and hsp70 expression in chick embryonic development: role of cAMP and hypoxia.

In the second half of avian embryonic development cAMP affects major aspects of red blood cell (RBC) function. At day 13/14, progressive developmental hypoxia causes the release of norepinephrine and erythroid beta-adrenergic receptor stimulation initiates the coordinate induction of adaptive key events of erythroid differentiation like carbonic anhydrase (CAII) and 2,3-biphosphoglycerate synthesis. Although cAMP-dependent regulation of CAII protein synthesis has been described in detail, no data exist about the transcriptional regulation in embryonic RBC. Here we report that after day 12 of embryonic development, the caII mRNA is accumulating. Hypoxic incubation at day 10 as well as in vitro incubation of isolated RBC with cAMP-elevating agonists strongly induces erythroid caII expression. The induction of caII occurs fast and does not require new protein synthesis. By screening several late erythroid genes, we could identify hsp70 as another cAMP-induced gene in definitive RBC. Because caII (but not hsp70) is also induced by cAMP in primitive RBC, the signal may regulate key events of late primitive and definitive erythropoiesis.

Adrenergic beta-Antagonists↗
PubMed2001

In search of pathogenic mechanisms in endometriosis: the challenge for molecular cell biology.

Endometriosis, defined histologically as the presence of endometrium-like glands and stroma outside the uterus, is a chronic, invasive and metastasising disease. It shares features with malignant tumours (invasion and metastasis) but is not neoplastic. Despite the fact that endometriosis is one of the most frequent gynaecological diseases, it is under researched, puzzling and highly debated. The aetiology and pathogenesis is little understood although it is agreed that implantation, at least in many cases, is responsible for endometriosis. This theory advocates retrograde menstruation as the underlying phenomenon, where cells of the menstrual efflux provide the cellular source for endometriotic lesion formation. Causative therapy and non-invasive diagnostics of endometriosis do not exist. Thus, there is a substantial but unmet need for molecular and cellular research to unravel the pathogenic mechanisms of endometriosis as a basis for developing novel diagnostic and therapeutic concepts. In this review, we specifically focus on the cellular basis of lesion formation, the possible modulation of this by cytokines and other factors and the characteristics of endometriotic cells in terms of invasion and metastasis. Considering available experimental information, we concentrate on arguments and ideas in favour of an endometriotic founder cell population exhibiting substantial plasticity for differentiation and self-renewal. Perhaps present in the menstrual efflux or arising by metaplasia (a complementary theory to implantation), this cell type might respond to stimuli present in the ectopic host environment and establish the endometriotic phenotype.

Cell Differentiation↗
PubMed2000

[Splenic thrombosis and celiac disease: a fortuitous association?].

BACKGROUND: Rare cases of venous thrombosis associated with celiac disease have been reported. CASE REPORT: We report a case of 40-year-old woman with splenic infarction and splenic venous thrombosis associated with celiac disease. This patient was homozygous for the C677T mutation of the methyltetrahydrofolate reductase (MTHFR) gene and had moderately elevated homocysteinemia. DISCUSSION: We discuss the link between celiac disease and thrombosis as well as the interest and appropriate duration of anticoagulation and hypothesize a mechanism of thrombotic disease in this setting with hyperhomocyseinemia.

Abdominal Pain↗