The inanimate environment of an intensive care unit as a potential source of nosocomial bacteria: evidence for long survival of Acinetobacter calcoaceticus

Environmental surface and personnel hand impression cultures were obtained during 13 sampling periods in the University of Virginia Pediatric Intensive Care Unit to document potential reservoirs of nosocomial pathogens. In 78 environmental cultures Staphylococcus aureus was found eight times and gram-negative bacilli ten times. The patient chart cover was the most commonly contaminated surface. Acinetobacter calcoaceticus was found in five of ten cultures positive for gram-negative bacilli. Thirty of 59 hand cultures were positive for S aureus and gram-negative bacilli; nurses and residents had both, respiratory therapists only gram-negative bacilli, and A calcoaceticus was the most commonly isolated bacterium of potentially nosocomial significance (14/30). Laboratory investigation of bacterial survival revealed that gram-negative bacilli survived on a dry formica surface from a few hours up to three days but Acinetobacter survived up to 13 days. Since A calcoaceticus has been implicated in many nosocomial infections, its long survival on a dry surface may be an additional factor in its transmission in hospitals and suggests that more attention be paid to environmental surfaces as a source of significant nosocomial pathogens.     

Thrombocyte function in children with Type I diabetes mellitus. Cross-sectional study]

Platelet count, spontaneous platelet aggregation, ADP- and collagen-induced platelet aggregation platelet adhesion, platelet volume, shape change, beta-thromboglobulin and von-Willebrand-factor have been investigated in 51 insulin dependent diabetic children without clinical signs of diabetic angiopathy. Compared to an age matched healthy control group diabetic children showed a significant enhancement of spontaneous platelet aggregation, elevated plasma levels of von-Willebrand-factor, increased platelet shape change and adhesion. No alterations could be found in ADP--and collagen--induced platelet aggregation and in beta-thromboglobulin levels. Significant correlations could be found between the total glycosylated haemoglobin concentrations (Hb A1) and spontaneous platelet aggregation, as well as between duration of diabetes Hb A1, and platelet volume. In this study we could demonstrate changes in platelet function in diabetic children without clinical signs of diabetic angiopathy. However these changes could be due to metabolic adjustment and may precede diabetic vasculopathy.     

Knee complaints in patients with normal arthroscopic findings

Clinical follow-up was obtained in 96 patients with knee complaints but normal arthroscopic findings (mean observation time, 10 months). About one-third had no symptoms at follow-up; in another third there was improvement; in the remaining third there were unchanged or worsened symptoms, and a clinical re-examination indicated that alterations in the soft tissues around the knee might explain the worsening. However, 10 patients in the last group had not only significant worsening of the knee symptoms but also severe complaints in other regions of the body and a psychosomatic factor was suspected. Most of the patients with symptoms at follow-up had significant wasting of the quadriceps muscles. Energetic exercises seem important even in patients with normal arthroscopic findings.     

Funktionelle Schluckaktuntersuchungen mit der Elektronenstrahl- computertomographie

Zusammenfassung Videofluorographie und Kinematographie gelten derzeit als Goldstandard für die Abkl?rung von Schluckst?rungen. Methodisch bedingt ist jedoch keine überlagerungsfreie Darstellung der anatomisch wichtigen Strukturen des Pharynx m?glich, so da? bei manchen St?rungen nicht unterschieden werden kann, ob diese pathoanatomisch oder funktionell-neurogen bedingt sind. Anhand von 3 Fallbeispielen wird dargelegt, ob und in welchem Umfang die Elektronenstrahlcomputertomographie mit ihrem hohen r?umlichen und zeitlichen Aufl?sungsverm?gen (Millisekundenbereich) diese Nachteile kompensiert. Es ist uns gelungen zu zeigen, da? die vollst?ndige und symmetrische nasopharyngeale Abdichtung durch den Passavantschen Wulst und den weichen Gaumen gew?hrleistet wird. Durch die EBT konnte die genaue anatomische Lokalisation und Ausbreitung eines lateralen hypopharyngealen Pouches dargestellt werden. Durch den Nachweis einer Kompression des oberen ?sophagussphinkters durch einen kleinen zervikalen Spondylophyten konnte eine scheinbar nur funktionell bedingte Dysfunktion weiter abgekl?rt werden. Diese Beispiele zeigen, da? die Elektronenstrahlcomputertomographie die sich funktionell ?ndernde Anatomie w?hrend des Schluckens in der Transversalschicht darstellen kann, und legen es nahe, ihre Wertigkeit auf der Basis systemischer interdisziplin?rer Untersuchungen zu evaluieren.      

Profound increase ofHelicobacter pylori urease activity in gastric antral mucosa at low pH

The effect of pH onH. pylori urease activity in its ecological niche was studied in gastric antral biopsy specimens. Specimens were incubated in 10 mmol/liter urea solutions at pH range 3.3–8.2. Activity of urease was studied by measuring production of ammonia and change in pH of the solutions. Urease activity was reduced at pH 8.2 (1424 ± 218 µmol/liter) but decreasing initial pH to neutral and acidic values resulted in significant maximal 6.5-fold increase in ammonia production (9491 ± 1073 µmol/liter,P<0.0005), which considerably raised the pH of the test solutions. Peak urease activity was between pH 5.0 and 7.0. In contrast to specimens incubated initially at pH 8.0, reincubation of washed specimens from solutions with initial pH 7.0 showed eightfold decreased urease activity. It is concluded that urease activity is markedly pH dependent with pH optima below the physiological mucosal surface pH. Furthermore, availability of urease is limited. Thus, an impaired gastric mucosal integrity allowing back diffusion of hydrogen ions may release urease activity, which might further weaken the mucus barrier and damage the gastric epithelium.This study was supported by the Deutsche Forschungsgemeinschaft (Mi 190/3).     

The mode of action and the structure of a herbicide in complex with its target: binding of activated hydantocidin to the feedback regulation site of adenylosuccinate synthetase.

(+)-Hydantocidin, a recently discovered natural spironucleoside with potent herbicidal activity, is shown to be a proherbicide that, after phosphorylation at the 5' position, inhibits adenylosuccinate synthetase, an enzyme involved in de novo purine synthesis. The mode of binding of hydantocidin 5'-monophosphate to the target enzyme was analyzed by determining the crystal structure of the enzyme-inhibitor complex at 2.6-A resolution. It was found that adenylosuccinate synthetase binds the phosphorylated compound in the same fashion as it does adenosine 5'-monophosphate, the natural feedback regulator of this enzyme. This work provides the first crystal structure of a herbicide-target complex reported to date.     

Prolactin in patients with major depressive disorder and in healthy subjects. II. Longitudinal study of basal prolactin and post-TRH-stimulated prolactin levels

Longitudinal investigations of basal prolactin (PRL) and prolactin concentrations following thyrotopin-releasing hormone (TRH) stimulation (delta PRL) were conducted in 17 patients with major depressive disorder and healthy subjects. The patients were being treated with either clomipramine or maprotiline. Both basal and delta PRL increased significantly after clinical response during treatment with both drugs. However, these increases in basal and delta PRL were independent of each other. Surprisingly, elevations of basal PRL were significantly greater in responders than in nonresponders, whereas those in delta PRL showed no corresponding significant difference. These results suggest that the two drugs stimulate basal and delta PRL by different mechanisms. The increases in basal prolactin levels found in responders may possibly be due to weaker inhibition of prolactin due to "down-regulated" beta adrenergic receptors and/or enhanced activity of supersensitive serotonergic receptors. Neither basal PRL nor delta PRL proved to be a predictor of therapy response. The intraindividual retest reliabilities of both basal and delta PRL in healthy subjects was so good that a single blood sample would seem to be sufficient for investigating most issues involving PRL in psychiatric patients.     

Triperidin (Norakin): separation, stability and structure of stereoisomers

The antiparkinsonian triperiden (1; as hydrochloride Norakin) is a mixture of the stereoisomers 1a and 1b. Their identification and separation by chromatographic methods or fractional crystallisation of the tartrates is described. By means of IR- und 13C-NMR spectral data structures of 1a and 1b are proposed. Under proton catalysis 1b racemizes to 1a. In acidic solution (heating in 0.1 mol.1-1 HCl or storage in gastric juice at 37 degrees C) hydrolysis of 1 takes place and four isomeric products were observed (Z1-Z4), which arise by cleavage of the cyclopropyl moiety. The main product Z2 was identified as the 2"-hydroxy derivative. The solid drug is stable at least for 5 years.