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Biomedical subjects

R Baumann

Publications and source records attributed to R Baumann.

At least 289 records · Page 16Linked to original sources
PubMedDate not supplied

Monk seal mortality: virus or toxin?

During the past few months, more than half of the total population of about 300 highly endangered Mediterranean monk seals (Monachus monachus) on the western Saharan coast of Africa, died in a mysterious disease outbreak. Epizootiological and postmortem findings were reminiscent of similar outbreaks amongst pinniped and cetacean species in recent years, which were caused by an infection with newly discovered morbilliviruses (for review see osterhaus et al.). Virological, as well as toxicological, analysis performed on tissue samples collected from relatively fresh carcasses during the outbreak indicate that infection with a virus closely related to dolphin morbillivirus (DMV), possibly originating from affected dolphins in the same area, was the primary cause of the outbreak. Therefore it is concluded that vaccination with a safe and effective non-replicating vaccine should be considered as a management tool in the conservation of Mediterranean monk seals.

Africa, Western↗
PubMedDate not supplied

[Endometriosis--a stem cell disease?].

Endometriosis is an estrogen-dependent and chronic disease with an unknown etiology and pathogenesis. It is however likely and well accepted that retrograde menstruation of endometrial cells into the pelvic cavity is the origin of this disease in many cases. Here we discuss a model in which retrogradely menstruated endometrial cells have different inherent developmental properties because they represent in fact a mixture of different developmental cell stages. These stages can be distinguished in part by the expression of marker proteins such as cytokeratin (intermediate filament protein of epithelial cells) or E-cadherin (intercellular adhesion protein of epithelial cells and metastasis suppressor molecule). Cytokeratin-positive E-cadherin negative cells, for example, would be less differentiated epithelial cells than cytokeratin-positive E-cadherin positive cells. In analogy to findings in other cell systems we assume that the cells which are undifferentiated or not fully differentiated still have the potential to give rise to differentiated daughter cells and, on the other hand, could be maintained as a pool of rather undifferentiated cells and capable of self renewal. This feature would be similar to stem cells (SC) and cells with plasticity. Interestingly we find epithelial cells of different developmental stages in deep infiltrating (e. g. of colon) or peritoneal endometriotic lesions. Therefore we conclude that less differentiated cells in retrogradely menstruated endometrial cell populations possibly representing SC features or plasticity might be the cellular source of primary endometriotic lesions and those present in lesions may contribute to the persistence of the disease by detaching and forming secondary lesions.

Cell Differentiation↗
PubMedDate not supplied

Ethics and reproductive medicine.

This article surveys relevant moral and ethical implications of reproductive medicine, excluding any aspects of contraception. To maintain the methodological priority of a moral perspective, it focuses on moral theory and ethics in general before looking at the impact of ethics on the different techniques applied in reproductive medicine. We suggest that discourse ethics should be centre-stage among the moral perspectives, since it has a unique capacity to synthesize, gauge and emulate other moral perspectives without necessarily replacing them. Questions of spousal fidelity, parental identity, sexual relations, reshaping of family ties, preimplantation diagnosis, discarding of human life, up to the question of what kind of life is generally acknowledged as worth living, and which is not, all these are morally significant topics. As well as providing a description of the techniques used in reproductive medicine, our article presents a rationale for charting potentials for moral problems. This renders it possible to elucidate the moral costs of each of the options offered by reproductive medicine in the light of whatever moral view one identifies with.

Cryopreservation↗
PubMedDate not supplied

Tracing cellular and molecular mechanisms involved in endometriosis.

The aetiology and pathogenesis of endometriosis, defined as the presence of endometrium-like tissue outside the uterine cavity, is largely unknown. In this paper we present and discuss possibilities to study the putative pathogenic properties of endometriotic cells in vitro. The current focus of our investigations is on the invasive phenotype of the disease, assuming that this might contribute to the pathogenesis of endometriosis. So far, we have shown that: (i) cytokeratin-positive and E-cadherin-negative endometriotic cells have an invasive phenotype in a collagen invasion assay in vitro similar to metastatic carcinoma cells; (ii) the invasiveness of endometriotic but not of eutopic endometrial cells can be stimulated by a heat-stable protein present in peritoneal fluid; and (iii) the endometriotic cell line EEC145T, which we established, may be a useful tool for the identification of gene products which are, positively or negatively, invasion-related. Finally, our studies suggest that the invasive phenotype in endometriosis shares aspects with tumour metastasis, but might also have unique mechanisms.

Ascitic Fluid↗
PubMedDate not supplied

Experimental studies on the treatment of unilateral vocal cord paralysis.

After the injection of Teflon and Silicon behind the vocal cords of sheeps we noticed that these materials are quite well supported. The little particles of Teflon are surrounded by conjective tissue wheras the Silicon is enclosed in an unic membrane. We could not see a migration of the materials in the depth.

Animals↗
PubMedDate not supplied

[Diagnostic value of high resolution sonography in Crohn's disease and ulcerative colitis].

OBJECTIVE: To evaluate the diagnostic accuracy of high resolution sonography in patients with inflammatory bowel disease (MICI). PATIENTS AND METHODS: In patients with Crohn's disease (n = 48), ulcerative colitis (n = 23), indeterminate colitis (n = 3), inflammatory (n = 21) and non-inflammatory (n = 23) controls, high resolution sonography was performed and compared to colonoscopy (+/- retrograde ileoscopy) and/or baryum studies of the small bowel and the colon. RESULTS: Diagnosis of intestinal inflammation or not was correct in 69/74 MICI patients (sensitivity: 94.4%, specificity: 66.7%, global accuracy: 93.2%). Segment location was accurate in 58/74 (sensitivity: 80.3%, specificity: 66.7%, global accuracy: 79.7), more frequently in Crohn's disease, than in ulcerative colitis. Five out of six complications of Crohn's disease were diagnosed. In Crohn's disease, the method was more accurate in case of colonic or ileocolonic involvement. CONCLUSION: High resolution sonography is a reliable diagnostic tool for the detection of intestinal inflammation and related complications in MICI. In can be of value in the follow-up and seems particularly interesting in the case of temporary contraindication of invasive methods.

Colitis, Ulcerative↗
PubMedDate not supplied

[Non-surgical treatment of cysts and pseudocysts of the pancreas. A study of a series of 33 cases].

Pancreatic cysts and pseudocysts had to be treated by surgery until 15 years ago. Nowadays they can be aspirated (or drained) either endoscopically or by ultrasonic and computed tomographic guided punctures. The aim of this study was to see if these non-surgical treatments were efficient enough among the actual treatments. From 1984 to 1988, 33 patients were admitted in one single institution with a pancreatic cyst or pseudocyst, 22 of which were a consequence on an acute pancreatitis and 11 complicated a chronic pancreatitis. Ten cysts were connected with the Wirsung channel while 11 others were not, but the ERCP failed to give any accurate information on this point in 12 cases. As a first treatment, we abstained of any invasive procedure in 9 cases, 18 were treated by percutaneous aspiration guided by ultrasound and 6 patients underwent surgery. The mean follow-up was 30 months. All the patients who had no treatment remained symptom free; their cysts improved in 5 cases and disappeared in 4 cases. Among the cysts treated by percutaneous aspiration, 4 had to be operated, 5 disappeared, 3 improved and 6 recurred; the percutaneous aspiration obtained a lasting symptoms' relief for these patients, whatever the connection the cyst had with the Wirsung channel. This study suggests that percutaneous aspiration or drainage guided by ultrasound may be a treatment of the highest quality for acute and chronic pancreatitis cystic formations. However, it seems to act upon the symptoms rather than upon the cystic formations themselves.

Adult↗
PubMedDate not supplied

[Efficacy of endoscopic pneumatic dilatation in achalasia. Medium-term results].

During a seven-year period, thirty patients with achalasia of the esophagus were treated by pneumatic dilatation without complications. Only twenty patients could be followed with a mean follow of 32 +/- 23 months after their initial dilatation. Excellent to good results were obtained in more than 75 p. cent of the group. Most patients have not required a further dilatation. This study suggest to propose a regular supervision of these patients by clinical examination, esophageal manometry and endoscopy.

Adult↗