Adhesion of Escherichia coli under flow conditions reveals potential novel effects of FimH mutations.

FimH-mediated adhesion of Escherichia coli to bladder epithelium is a prerequisite for urinary tract infections. FimH is also essential for blood-borne bacterial dissemination, but the mechanisms are poorly understood. The purpose of this study was to assess the influence of different FimH mutations on bacterial adhesion using a novel adhesion assay, which models the physiological flow conditions bacteria are exposed to. We introduced 12 different point mutations in the mannose binding pocket of FimH in an E. coli strain expressing type 1 fimbriae only (MSC95-FimH). We compared the bacterial adhesion of each mutant across several commonly used adhesion assays, including agglutination of yeast, adhesion to mono- and tri-mannosylated substrates, and static adhesion to bladder epithelial and endothelial cells. We performed a comparison of these assays to a novel method that we developed to study bacterial adhesion to mammalian cells under flow conditions. We showed that E. coli MSC95-FimH adheres more efficiently to microvascular endothelium than to bladder epithelium, and that only endothelium supports adhesion at physiological shear stress. The results confirmed that mannose binding pocket mutations abrogated adhesion. We demonstrated that FimH residues E50 and T53 are crucial for adhesion under flow conditions. The coating of endothelial cells on biochips and modelling of physiological flow conditions enabled us to identify FimH residues crucial for adhesion. These results provide novel insights into screening methods to determine the effect of FimH mutants and potentially FimH antagonists.

Morphological changes in peripheral blood cells and skin in amiodarone-treated patients.

Amiodarone, used in the treatment of cardiac arrhythmia, may lead to severe discolouration of sun-exposed skin. The lysosomal storage of a lipid-like material has been shown to be the morphological substrate for this cutaneous hyperpigmentation. Examination of peripheral white blood cells of amiodarone-treated patients disclosed identical lysosomal structures indicating that amiodarone treatment leads to a more generalized lysosomal storage of lipids and of amiodarone and its metabolites.

[Aortofemoral bifurcation bypass. Effect of the anesthesia procedure (NLA, thoracic continuous catheter peridural anesthesia) on circulation, respiration and metabolism. Homeostasis and oxygen transport]. / Aortofemoraler Bifurkationsbypass. Der Einfluss des Anaesthesie-verfahrens (NLA, thorakale kontinuierliche Katheterperidural-anaesthesie) auf Kreislauf, Atmung und Stoffwechsel. Homöostase und Sauerstofftransport.

50 patients were investigated during induction of anaesthesia and infrarenal aortic bypass surgery. 26 were operated on under neuroleptanaesthesia (NA group) and 24 under continuous epidural combined with a light general anaesthesia (epidural group). Blood losses were replaced with 5 per cent human albumin, red cell concentrates, and fresh frozen plasma. Ringer lactate solution was used to replace the functional extracellular fluid volume. During induction and maintenance of anaesthesia body temperature fell (NA group from 36.7 to 35.3 degrees C; epidural group from 36.7 to 34.9 degrees C) but no statistically significant difference could be found between the groups, in spite of better surface perfusion of the lower part of the body in the epidural group. The increase of plasma glucose concentration was lower in the epidural group as compared to the NA group. Stress mediated hypokalaemia was of the same degree in both groups, the median values of the plasma potassium concentrations being in the lower reference range (3.5-3.7 mmol X 1(-1], although large amounts of red cell concentrates were given. During clamping of the aorta a moderate compensated acidosis developed in both groups. Declamping caused a more marked increase of paCO2 and a greater fall of pH in the NA group as compared to the epidural group. Induction of anaesthesia was followed by a fall in oxygen uptake (NA group from 221 to 163 ml X min-1; epidural group from 230 to 189 ml X min-1) which appears to be delayed in the epidural group, with a short lasting statistically significant difference between the groups after eventration of the gut (NA group: 162 ml X min-1 less than epidural group 184 ml X min-1). Later on, oxygen uptake was equal in both groups, with no further changes due to clamping or declamping of the aorta. At the end of the operation, when nitrous oxide had been turned of, the oxygen uptake increased considerably in several patients, despite continuing artificial ventilation and intravenous hypnotics and analgesics having been given. Eventration and exterioration of the gut caused the most marked changes in haemodynamics and oxygen transport with significant differences between the groups. Immediately after eventration there was a sudden fall in paO2 in both groups (NA group from 99 to 83 mm Hg; epidural group from 96 to 84 mm Hg) and an increase of the calculated intrapulmonary right-to-left-shunt (NA group from 7 to 21%; epidural group from 10 to 19%).(ABSTRACT TRUNCATED AT 400 WORDS)

[Unusual molluscum contagiosum infection in sarcoidosis]. / Ungewöhnliche Molluscum-contagiosum-Infektion bei Sarkoidose.

An extremely extension of molluscum contagiosum infection of the skin of a 42 year old man led to detection of pulmonary sarcoidosis. Viral infection can be the result of impaired cellular immunity caused by various diseases or by immunosuppressive therapy. In our case sarcoidosis was the base for an unusual serious course of a molluscum contagiosum infection.