Search PubMed⌕ Search

Biomedical subjects

D Schumann

Publications and source records attributed to D Schumann.

106 records · Page 6Linked to original sources
PubMedDate not supplied

[Silent persistent ductus arteriosus].

We report on 14 observations undertaken by ourselves of silent persistent ductus arteriosus (SPDA). During a three year period with the routine use of color doppler flow evaluation we found cases of SPDA in 14 children. A very little ductus arteriosus is already known to us through earlier heart catheter examinations which were undertaken because of other isolated heart defects (16 cases in 345 isolated heart defects over 10 years). We also consider the fact that SPDA is not an infrequent result after the occlusion of a patent ductus arteriosus with the Rashkind-Occluder-System and after operative ligatures of patent ductus arteriosus. Finally, we compare our results concerning the frequency of SPDA with current literature and discuss consequential therapies.

Blood Flow Velocity↗
PubMedDate not supplied

Treatment of human mesenchymal stem cells with pulsed low intensity ultrasound enhances the chondrogenic phenotype in vitro.

This study examined the effects of low intensity pulsed ultrasound (LIPUS) on human bone marrow-derived mesenchymal stem cells undergoing chondrogenic differentiation. Aggregates of mesenchymal stem cells and mesenchymal stem cells seeded in three dimensional matrices were cultured in a defined chondrogenic medium and subjected to LIPUS for the first 7 days of culture. At 1, 7, 14 and 21 days, samples were harvested for histology, immunohistochemistry, RT-PCR, and quantitative DNA and matrix macromolecule analysis. Cell aggregates with daily treatment for 20 minutes showed no significant differences for proteoglycan and collagen content during chondrogenic differentiation. However ultrasound application for 40 minutes daily resulted in a statistically significant increase of the proteoglycan and collagen content after 21 days in culture. Aggregates treated for 20 minutes daily showed decreased expression of chondrogenic genes at all time points. In contrast, 40 minutes of daily treatment of aggregates resulted in a significant increase of chondrogenic marker genes after an initial decrease at day 7 with time in culture. Ultrasound treated cell-scaffold constructs showed a significant increase of chondrogenic marker gene expression and extracellular matrix deposition. This study indicates that LIPUS can be used to enhance the chondrogenesis of mesenchymal stem cells in cell aggregates and cell-scaffold constructs. We have found a dependency on the specific treatment parameters. We hypothesize that LIPUS can be used for an improved in vitro preparation of optimized tissue engineering implants for cartilage repair. Furthermore this non-invasive method could also be of potential use in vivo for regenerative therapy of cartilage in the future.

Aggrecans↗
PubMedDate not supplied

Sublingual nifedipine controversy in drug delivery.

Nifedipine, given sublingually, has become increasingly common for treatment of cardiovascular crises. While this may seem an expedient and safe method to reduce blood pressure, controversial issues have surfaced that emphasize the need for cautious drug delivery. Moreover, sublingual administration of nifedipine is not currently approved by the Food and Drug Administration.

Administration, Sublingual↗
PubMedDate not supplied

Nitrous oxide anaesthesia: risks to health personnel.

Although nitrous oxide is the most commonly administered inhalation anaesthetic, it is not an innocuous agent. Adverse haematologic, neurologic, immune and reproductive effects have been identified in health personnel, among them operating room nurses, anaesthetists and anaesthesiologists. These groups are especially vulnerable to toxicity, owing to trace amounts that may accumulate over a lifetime from occupational exposure. Worldwide, nitrous oxide is commonly used for obstetric analgesia, placing midwives and obstetric nurses among those susceptible to toxicity from excessive and lengthy contact. Despite standards to control hazardous exposure, health personnel cannot become complacent with its use. Below, an examination of current evidence about exposure risks to health personnel and a review of the status of research explaining the genesis of organ-related dysfunction.

Delivery Rooms↗
PubMedDate not supplied

[Partial characterization of the epithelial lectin binding sites of human gingiva and skin].

Frozen sections of human gingiva and skin, fixed in acetone, were subjected to limited enzyme digestion (neuraminidase, proteinase K, trypsin) or, respectively, the application of solvents (chloroform/methanol, triton X-100) to allow a partial characterization of epithelial lectin binding sites. Gingiva differs from normal skin in that more conA-binding glycolipids are present in the lower cell layers. In the upper layers conA-fixing glycoproteins are prevailing. Psoriatic foci regularly exhibit an increased presence of conA-binding glycolipids. Gingiva and normal skin have some common features in the behavior of the lectin binding sites of HPA, WGA and UEA I. Analogies in the binding pattern of conA and UEA I in gingival tissue and in psoriatic foci are thus due to different lectin receptors.

Binding Sites, Antibody↗
PubMedDate not supplied

Homogeneity of potassium chloride in small volume intravenous containers.

The purpose of this investigation was to determine whether potassium chloride as an additive is distributed homogeneously throughout small volume parenteral solutions and whether the pattern of electrolyte distribution is identical for two types of delivery systems. The effect of purposeful mixing after addition of potassium chloride was also studied. Thirty-one registered nurses prepared two supplementary intravenous solutions consisting of 10mEq potassium chloride in 50ml of 5% dextrose solution. One solution was prepared in a soft polyvinyl chloride minibag (Viaflex, Baxter-Travenol), the other in a semirigid plastic burette (Buretrol, Baxter-Travenol). The solutions were discharged through a volumetric pump (IMED) and four aliquots were taken at regular intervals. Samples were chemically analyzed by flame photometry to determine the potassium concentration in each solution layer of the container. For each container type, there were significant differences in the potassium concentrations among the layers of solution. The pattern of distribution also differed significantly between the two containers. The strata in the minibag showed smaller variations in potassium concentration than did corresponding layers in the burette. Some single sample concentrations from burettes exceeded the expected concentration of 200mEq/L by 105mEq. Nurses manipulated the two types of containers differently. Thirty of 31 minibags were mechanically mixed, but only 11 of 31 burettes were treated in this way. When the effect of mixing was considered, solutions in mixed containers were essentially no different from those not agitated after addition of the electrolyte.

Drug Packaging↗