Rapid detection of Salmonella sp. by means of a combination of selective enrichment broth and MALDI-TOF MS.

The identification of Salmonella sp. in stool samples usually takes 2 days when employing routine procedures. Fast approaches are necessary in order to shorten the analysis time. The aim of this work was the development of a rapid procedure for the detection of Salmonella sp. from clinical stool samples. Spiked stool samples were cultured in selective selenite enrichment broth. Identifications were directly performed from the liquid broth by the MALDI Biotyper. After the evaluation of this method, the same procedure was applied to clinical samples. Coevally, the samples were streaked on Hektoen agar and single colonies were analyzed by the MALDI Biotyper. For comparison, the liquid broth was plated according to the standard laboratory procedure. A total of 4,847 samples were analyzed for Salmonella sp. In total, 108 Salmonella sp.-positive samples were identified; 66 of these were identified after the streaking of stool samples on Hektoen agar and subsequent MALDI Biotyper analysis of Salmonella sp. suspicious colonies. These and a further 34 samples were detected as Salmonella sp.-positive directly from the selenite enrichment broth on day one. Eight Salmonella sp.-positive samples were not detected before plating of the selenite broth and subsequent MALDI Biotyper analysis on day two. The combination of MALDI Biotyper analysis and selective selenite enrichment broth identification delivers positive results for the majority of the samples already after one day.

Analysis of rhG-CSF-effects on platelets by in vitro bleeding test and transcranial Doppler ultrasound examination.

Experimental evidence suggests a stimulatory effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on both platelets and coagulation. RhG-CSF is increasingly used to stimulate healthy volunteer donors for blood stem cell mobilization. We therefore assessed 25 healthy donors receiving rhG-CSF for changes in in vitro bleeding test (IVBT), coagulation parameters and cerebral microembolism by transcranial Doppler (TCD) ultrasound. A significant shortening of IVBT was found on day 4 of rhG-CSF administration together with increased levels of fibrinogen and factor VIII and reduced activities of protein C and protein S. Although these changes are quite small it is possible that they may lead to a hypercoagulable state especially in donors with other risk factors for thromboembolism. However, TCD examination failed to detect any signs of microembolism. We therefore conclude that rhG-CSF leads to significant changes in coagulation parameters, but has no effect on TCD detectable microembolism as a stroke risk factor. However donors receiving rhG-CSF should be examined carefully to detect pre-existing changes in the coagulation system and we would like to suggest a routine thrombophilia screen.

Anticoagulation with r-hirudin in a patient with acute renal failure and heparin-induced thrombocytopenia.

After a Caesarean section subcutaneous bleeding with a secondary infection occurred accompanied by acute renal failure. Additionally the diagnosis of a heparin-induced thrombocytopenia type II could be made. Therefore, haemodialysis treatments were performed with r-hirudin as an alternative anticoagulation. Even in dialysis dependent acute renal failure a safe anticoagulation with r-hirudin is possible if aPTT and plasma r-hirudin are closely monitored.

Cytotoxicity of adriamycin, idarubicin, and vincristine in acute myeloid leukemia: chemosensitization by verapamil in relation to P-glycoprotein expression.

A 4-day colorimetric tetrazolium dye (MTT) assay was used to assess the cytotoxicity of adriamycin (ADM), vincristine (VCR), and idarubicin (IDA) in blasts isolated from 37 patients with newly diagnosed and pretreated acute myeloid leukemia (AML). The effect of verapamil (VRP) as a chemosensitizer was studied in relation to the expression of the membrane efflux pump P-glycoprotein (PGP) as determined by a semiquantitative flow-cytometric proceder. A slight positive correlation was found between the fraction of cells expressing PGP and the ID50 values for ADM and VCR, but not between cellular PGP content and sensitivity to IDA. The overall data showed no significant sensitization effect of VRP. However, in specimens with more than 10% cells expressing PGP, 2 microM VRP sensitized cells to ADM and VCR significantly. The median of sensitization ratios (SRs), i.e., the ratios of cytotoxic drug ID50 in the absence/presence of VRP, were 1.89 and 2.0, respectively. No sensitizing effect of VRP on the cytotoxicity of IDA was observed. Related to the clinical status, the median fraction of PGP-positive blasts was elevated fourfold in pretreated patients (n = 16) in comparison to patients with de novo AML (n = 19). No differences in ID50 values were observed between newly diagnosed and pretreated patients. However, SRs for ADM and VCR were higher in samples of pretreated patients compared with de novo AML. PGP-mediated cellular drug resistance may thus be circumvented in leukemic blasts by application of chemosensitizers or, potentially, alternative anthracyclines.

[Effect of rhG-CSF on platelets using in vitro bleeding time and transcranial Doppler examination]. / Untersuchung der rhG-CSF-Wirkung auf Plättchen mittels In-vitro-Blutungszeit und transkranieller Doppleruntersuchung.

There is experimental evidence for recombinant human granulocyte colony-stimulating factor (rhG-CSF)-induced stimulation of hemostaseologic parameters including platelets. Using the closure time of the in vitro bleeding test (IVBT, Thrombostat 4000, VDG, Seeon) and different hemostaseologic parameters, our results are suggestive of a directly or indirectly induced in vivo stimulation of platelets following rhG-CSF stimulation in healthy stem cell donors. According to the negative transcranial Doppler microembolic monitoring of the middle cerebral artery, there is no evidence for clinically silent cerebral microembolism supporting a prothrombotic state facilitating the formation of arterial thrombi with subsequent cerebral embolization.