Inoperable, functional relevant stenoses of the airways can be effectively treated short-termed and medium-termed by means of bronchoscopic stenting occasionally, silicone stents cause problems after long-term periods, such as migration and retention of bronchial secretions. Metallic stents can lead to obstructing granulomas or even bronchial wall perforation. As regards long-term treatment with airway stents over several years, there is little experience and no uniform recommendations are known. We report on a 76-year old female patient with a severe benign subglottic tracheostenosis after tracheostomy who was successfully treated by means of bronchoscopic dilatation and stenting with a silicone stent (POLYFLEX stent). POLYFLEX Stent is a self-expanding silicone stent with an encapsulated monofilament network made of polyester. The network is completely covered by a silicone layer with a smooth inner surface (protecting against incrustation) and a structured outer surface of the stent (protecting against migration). The ends of the monofilaments were provided with a special protection to avoid tissue granulation and to yield x-ray contrast. During a follow-up of almost 5 years the stent is well tolerated and there is no restenosis. Complications such as migration, obstructing secretions and obstructing granulomas did not occur. A slight bronchial hypersecretion presented no problem under regular inhalation therapy with isotonic NaCl solution. 21 and 56 months after stenting there were two episodes of minor haemoptysis. There was no demonstrable source of haemorrhage by bronchoscopy. After 56 months, biopsy at the distal opening of the stent showed a squamous cell metaplasia, but no granulation tissue. Microbiological analysis of bronchial secretions revealed an increasing, but clinically silent colonisation with potentially pathogenic microorganisms.

The accumulation and desorption of gaseous DDE in spruce needles was investigated in two chamber experiments using Picea omorika and in a third using Picea abies. The P. omorika needles were divided into two fractions for analysis: the soluble cuticular lipids and the remaining needle. The data were used to parameterize a one-compartment (complete needle) and a two-compartment (surface, reservoir) plant model. The one-compartment model performed poorly, whereas the uptake and clearance behavior of the complete needle was described very well with the two-compartment model. However, the two model compartments did not correspond to the two needle fractions that were analyzed for P. omorika. The validation of the P. abies model using environmental data was quite successful, whereas the validation of the P. omorika model gave poor results. It was concluded that chamber experiments are not sufficient for describing the air/plant exchange of contaminants for which the half-life of the exchange process with the slowest leaf compartment is longer than the length of the experiment. Furthermore, model validation is essential if the results of chamber experiments are to be extrapolated to environmental conditions.

Spruce needles (Picea abies) which had been exposed for 6 hours to elevated concentrations of gaseous SOC were immersed in dichloromethane for up to 100 minutes. It was found that compounds with higher molecular weights (PCBs, DDT and DDE) were completely removed from the needles after washing for several minutes. Large fractions of the compounds with lower molecular weight (chlorobenzenes and hexachlorocyclohexanes) could not be extracted by this method, even after immersion for 100 minutes. These results are attributed to differences in the diffusion behavior of the two substance groups. For the SOC with higher molecular weights the cuticular lipids act both as a sink and as a diffusion barrier, whereas the SOC with lower molecular weight can readily penetrate into the interior of the needle. These results question contaminant models which assume that the leaf is a single, well mixed compartment. The solvent immersion extraction may be useful when employing needles as biomonitors, possibly circumventing the problem of very slow kinetic behavior in the whole needle.

Aldolase activity with the two substrates fructose-1-phosphate and fructose-1,6-diphosphate was measured in the homogenate of small intestinal biopsy specimens from children with different malabsorptive diseases (celiac disease, cow's milk protein intolerance, infectious diarrhea, giardiasis, and Crohn's disease) and controls. It is demonstrated that the ratio of fructose-1,6-diphosphate/fructose-1-phosphate activity, which reflects the relative amounts of the crypt enzyme aldolase A (EC 4.1.2.13) and the villous enzyme aldolase B (EC 4.1.2.7), correlates very well with both the ratio of crypt to villous height (correlation factor r = 0.92) and the mitotic index (r = 0.80).

Die klinische Anwendung stromahaltiger sowie stromafreier Hämoglobinlösungen als sauerstofftransportierende Volumenexpander bei der Therapie akuter Blutverluste wurde bisher durch tierexperimentell beobachtete nephrotoxische Wirkungen in Frage gestellt (Miller u. McDonald; Goldberg; Schneider et al.; Unseld et al. (1976)).

Solutions of stroma free human hemoglobin and of polymerized hemoglobin were used for perfusion of isolated organs of the experimental animal (Wistar rats). Both preparations proved to be suited for maintainance of sufficient oxygen transport. Following intravenous infusion of greater amounts of hemoglobin or polymerized hemoglobin in the experimental animals (3.0 g/kg body weight), the renal losses amounted 30% and less than 10% respectively. Half live was only two hours in the case of hemoglobin and 13 hours with the polymerized hemoglobin, despite molecular weight was only doubled in the latter preparation. Since the minor amount of the different hemoglobin preparation was excreted by the kidneys, the greater amount was stored in the organism or metabolized respectively. The intravenous infusion did not cause chemically demonstrable signs of liver toxicity. Neither bilirubin concentration nor enzyme activity showed significant alterations. Additionally, all animals survived the high dosed intravenous infusions. However, histological evaluations showed distinct alterations caused by the hemoglobin preparations. Hemoglobin was found inside the liver parenchymal cells. The liver cells and kidney cells showed signs of toxic effects. The polymerized hemoglobin was not found in liver parenchymal cells. In contrast to hemoglobin this preparation was stored inside the Kupffer's cells. In contrast to hemoglobin the polymerized form behaves like erythrocytes. The rapid elimination of hemoglobin (half live only two hours) renders this substance unsuited for blood substitution. However, half life of polymerized hemoglobin is 13 hours, and from this point of view the polymerized form is suited for blood substitution. Considering the histologically demonstrable alterations additional experiments are required before hemoglobin solutions are used in human subjects.

Stromafreies Hämoglobin (Humanhämoglobin) ist bei Verwendung von isolierten Organen geeignet, den Sauerstofftransport aufrechtzuerhalten. Das gleiche gilt für polymerisiertes Hämoglobin. Nach Infusion bei Versuchstieren ist allerdings nachzuweisen, daβ einfaches Hämoglobin eine recht geringe intravasale Verweildauer hat. Die Halbwertszeit beträgt lediglich zwei Stunden. Das polymerisierte Hämoglobin hat hingegen eine deutlich verlängerte Halbwertszeit von etwa 13 Stunden, obwohl das Molekulargewicht lediglich verdoppelt ist. Nur ein geringer Teil des intravenös verabreichten Hämoglobins wird über die Nieren ausgeschieden; bei einfachem Hämoglobin ca. 30 %, bei polymerisiertem Hämoglobin weniger als 10%. Der verbleibende Rest muβ innerhalb des Organismus metabolisiert werden. Bei Ratten kann bei den Akutbelastungen mit auβerordentlich hoher Dosierung (3 g/kg Körpergewicht) trotz des morphologisch nachweisbaren Zellschadens keine Veränderung der Leberfunktion festgestellt werden, während an den Nieren der Nachweis von Tubulusnekrosen eine bedeutsame Nierenschädigung signalisiert. Polymerisiertes Hämoglobin hingegen bewirkt keine Nierentubulusnekrosen und ist auch bei der morphologischen Untersuchung im Gegensatz zum einfachen Hämoglobin in den Parenchymzellen der Niere nur in.geringer Menge nachweisbar. Vielmehr erscheint es in der Leber in den Kupffer-Sternzellen, in denen es ähnlich wie die Erythrozyten abgebaut wird. Aufgrund der geringen intravasalen Verweildauer erscheint stromafreies Hämoglobin im Gegensatz zu polymerisiertem Hämoglobin ungeeignet für den akuten Blutersatz. Darüber hinaus machen jedoch die unter stromafreien Hämoglobinlösungen auftretenden Parenchymzellschäden deutlich, daβ die Verwendung von Hämoglobinlösungen als Blutersatzmittel zahlreiche Probleme aufwirft, die vor der Anwendung am Menschen eine sorgfältige Prüfung erfordern.

A 39-year-old woman contracted visceral leishmaniasis on a 14-day visit to southern Italy and died of staphylococcal septicaemia before specific treatment could be effective, diagnostic efforts over four months having failed to make the diagnosis until four weeks before death. Eight further cases reported in German-speaking medical journals illustrate similar diagnostic difficulties. The disease is accompanied by septic temperatures, frequently with two daily spikes, hepato- and splenomegaly, normochromic anaemia and leucocytopenia. But diagnosis can only be made by specific tests. The organisms can be discovered in sternal puncture and organ biopsies only if the Giemsa stain is used. Complement-fixation reaction for leishmania should be tried repeatedly, in case the disease is suspected.

A 39-year-old woman contracted visceral leishmaniasis on a 14-day visit to southern Italy and died of staphylococcal septicaemia before specific treatment could be effective, diagnostic efforts over four months having failed to make the diagnosis until four weeks before death. Eight further cases reported in German-speaking medical journals illustrate similar diagnostic difficulties. The disease is accompanied by septic temperatures, frequently with two daily spikes, hepato- and splenomegaly, normochromic anaemia and leucocytopenia. But diagnosis can only be made by specific tests. The organisms can be discovered in sternal puncture and organ biopsies only if the Giemsa stain is used. Complement-fixation reaction for leishmania should be tried repeatedly, in case the disease is suspected.