Political decision making in science and technology: A controversy about the release of genetically engineered organisms

In the policy-making process, there is increasing demand for scientific and technical information. But one of the major insights about science and technology recently highlighted by historians and philosophers is that in their development, science and technology are accompanied as much by internal controversy as by consensus. This creates a problem for the policy decision maker. How can a consensus in the policy making process be achieved in the context of scientific and technological controversy? This problem can be approached by analyzing the types of discussions in which scientific and technical experts participate, and is the topic of this paper.     

Stent implantation as a palliative therapeutic measure in stenosing tumors of central airways

PURPOSE: Stent implantation was used to treat patient with malignant tracheobronchial obstructions to determine the effectiveness in producing symptomatic palliation. METHODS: 18 patients (15 men and three women; median age 57 years) with malignant tracheobronchial stenosis were treated by application of metal stents (15 Palmaz-, 10 Gianturco-, 4 Wallstents). The indication for stent implantation was given in 13 patients by clinically significant dyspnea, besides in 5 patients by therapy resistant postobstructive pneumonia. RESULTS: In 17 patients correct positioning of the stents was achieved and the symptoms completely disappeared until tumor related death. Median survival was 137 days (min. 10 days to max. 322 days). In one patient symptoms recurred three months after stent implantation. CONCLUSION: The application of metal stents in patient with malignant tracheobronchial obstruction appears to be a useful palliation procedure. The treatment was well tolerated and very effective.     

Colloidal transport and agglomeration in column studies for advanced run-off filtration facilities--particle size and time resolved monitoring of effluents with flow-field-flow-fractionation.

The efficiency of road run-off filtration facilities based on ion-exchange materials is reduced by pollutants which are transported bound to particles. To quantify the factors governing particle transport phenomena, a simplified model consisting of quartz sand-filled columns representing the filter/soil was set up. Suspensions of artificial clays, cold water-extracted natural clays, and real run-off were used as model effluents. Five experiments were performed: breakthrough of a natural soil suspension, remobilization of a natural soil suspension after ionic strength-drop, the same two experiments with a suspension of the artificial clay mineral Laponite, and the remobilization of run-off accumulated on a column at high ionic strength with an ionic strength down-gradient. Short-interval effluent fractions were analysed by flow-field-flow-fractionation (F4) to obtain the size distributions of the colloids present. The size distributions of subsequent fractions were then plotted in a staggered arrangement to give three-dimensional graphs that are time- and particle size-resolved. With this method the subsequent release of different agglomerate sizes formed on the column could be shown for the artificial clay mineral, questioning its use as a model colloid. The combined particle size- and time-resolved plots proved to be a powerful tool for monitoring colloidal solids in column effluents.     

The role of echocardiography in preoperative diagnosis of cardiac risk in patients before non-cardiac surgical interventions

Echocardiography is a noninvasive method for cardiac evaluation. A review of the current literature shows that the routine use of echocardiography for assessing perioperative cardiac risk in patients undergoing noncardiac surgery can not be supported. Only patients with suspected relevant heart valve diseases, acute heart failure, cardiomyopathy or condition after heart or heart-lung transplantation may benefit from preoperative echocardiography. In patients with suspected or proven coronary artery disease stress echocardiography offers the most relevant additional information for the anaesthesiologist. However, because of the high financial and personal implications it should be reserved to those patients who are not able to perform a normal stress test. Besides in patients in whom transthoracic echocardiography doesn't offer sufficient information or is not possible transesophageal echocardiography plays only a minor role in preoperative cardiac evaluation.     

Biomechanical and esthetic considerations for maxillary anterior overdenture abutment selection

Maxillary canine teeth traditionally have been selected as overdenture abutments. Undesirable aspects associated with the use of maxillary canines as overdenture abutments are described. The use of maxillary lateral incisors as overdenture abutments offers vertical support to the prosthesis, favorable stress distribution, improved esthetics, and preservation of the premaxilla.     

Sequence differences between glycosylated and non-glycosylated Asn-X-Thr/Ser acceptor sites: implications for protein engineering

In N-glycosylated glycoproteins, carbohydrate is attached toAsn in the sequence Asn-X-Ser/Thr, where X denotes any aminoacid. However, the presence of this consensus peptide does notalways lead to glycosylation. We have compiled an extensivecollection of glycosylated and non-glycosylated Asn-X-Thr/Sersites and present a statistical study based on this data set.Our results indicate that non-glycosylated sites tend to befound more frequently towards the C termini of glycoproteins,and that proline residues in positions X and Y in the consensusAsn-X-Thr/Ser-Y strongly reduce the likelihood of N-linked glycosylation.Beyond this, there are no obvious local sequence features thatseem to correlate with the absence or presence of N-linked glycosylation.These findings are discussed in terms of the prediction andengineering of glycosylation sites in secretory proteins.     

Balneophotochemotherapy with 8-methoxypsoralen in lichen sclerosis et atrophicus

A 66-year-old woman with longstanding lichen sclerosus et atrophicus improved strikingly with PUVA bath photochemotherapy over a period of 6 weeks. The cumulative UVA dose was 31.7 J/cm2; the single UVA dose ranged from 0.3 to 2.3 J/cm2. After 16 treatment sessions, the sclerotic lesions had softened greatly, while after 24 treatments, the skin lesions were almost completely cleared and pruritus was diminished. Histopathological analysis of biopsy specimens from previously affected sites as well as 20 MHz ultrasound examinations showed almost no residual sclerosis. Although long-term results are not yet available, PUVA bath photochemotherapy seems to be a promising and effective new treatment modality without systemic side effects for patients with disseminated lichen sclerosus et atrophicus.