Action of Polymyxin B on Bacterial Membranes: Morphological Changes in the Cytoplasm and in the Outer Membrane of Salmonella typhimurium and Escherichia coli B

Though the primary action of the cationic antibiotic polymyxin B is against the membrane of susceptible bacteria, severe morphological changes are detected in the cytoplasm. Using fluorescence microscopy and a mono-N-dansyl-polymyxin B derivative, we could demonstrate aggregations of the antibiotic with cellular material, possibly nucleic acids and/or ribosomes. These aggregations were only produced by minimum inhibitory or higher concentrations of the antibiotic as shown with Salmonella and Escherichia strains differing in their polymyxin susceptibility. The outer membrane of Salmonella typhimurium revealed characteristic blebs when treated with polymyxin B. This was investigated by the gentle methods of spray-freezing and freeze-etching. The obtained electron micrographs suggest that the polymyxin-induced blebs are projections of the outer monolayer of the outer membrane. A possible mechanism of penetration of polymyxin B through the cell envelope of gram-negative bacteria is presented.     

Intravenous immunoglobulin: striving for appropriate use

BACKGROUND: Intravenous immunoglobulin (IVIG) is the mainstay therapy in human immune deficiency states characterized by qualitative and quantitative reductions in B cells. In addition, however, there is widespread use of IVIG in a number of other areas, including neuroimmunologic, infectious, dermatologic, hematologic, autoimmune, inflammatory and idiopathic disorders. In many of these cases, there are little objective data to support the use. METHODS: We performed a review of more than 400 publications in PubMed using the key words 'intravenous immunoglobulin' and excluded publications that focused on immune deficiency, for which the indication for IVIG is already clear. RESULTS: For a number of off-label indications, there is significant evidence of efficacy and IVIG has become the standard of care for many clinical syndromes other than immune deficiency. In some conditions, however, the data have not been well controlled or randomized and are often limited to case reports that are difficult to interpret. Although the critical shortage of IVIG of the last decade is no longer an issue, IVIG is expensive and not without risk. The use of IVIG should be based not only on clinical data, but also, and especially, on the biological rationale for its use. CONCLUSIONS: The appropriate use of IVIG is an important issue that is difficult to resolve, and will continue to challenge clinicians based on expense and potentially limited supply, including the intrinsic limitations of donor plasma. The establishment of national and international voluntary registries to report use of IVIG in disorders for which evidence is lacking would be a first step toward facilitating randomized, controlled clinical trials.     

GENOMIZER: an integrated analysis system for genome-wide association data

Genome-wide association analysis appears to be a promising way to identify heritable susceptibility factors for complex human disorders. However, the feasibility of large-scale genotyping experiments is currently limited by an incomplete marker coverage of the genome, a restricted understanding of the functional role of given genomic regions, and the small sample sizes used. Thus, genome-wide association analysis will be a screening tool to facilitate subsequent gene discovery rather than a means to completely resolve individual genetic risk profiles. The validation of association findings will continue to rely upon the replication of "leads" in independent samples from either the same or different populations. Even under such pragmatic conditions, the timely analysis of the large data sets in question poses serious technical challenges. We have therefore developed public-domain software, GENOMIZER, that implements the workflow of an association experiment, including data management, single-point and haplotype analysis, "lead" definition, and data visualization. GENOMIZER (www.ikmb.uni-kiel.de/genomizer) comes with a complete user manual, and is open-source software licensed under the GNU Lesser General Public License. We suggest that the use of this software will facilitate the handling and interpretation of the currently emerging genome-wide association data.     

Geschlechtsrolle und Schmerzerleben

INTRODUCTION: The aim of this study was to assess the relationship between gender role orientation and the prevalence of chronic pain. METHOD: The individual gender role orientation in a sample of 45 chronic pain patients (ICD 10 diagnosis, F 45.4) was compared to gender role orientation in a matched, pain-free control group. Gender role orientation was assessed by questionnaires on the self-attribution of stereotypic gender traits (GEPAQ) and on the extent of agreement with traditional feminine and masculine role norms (MRNS, FRNS). Group differences were compared by multivariate analysis. RESULTS: In accordance with the hypothesis, results confirmed that pain patients showed stronger feminine and weaker masculine role orientations than healthy controls. Pain patients additionally ascribed to themselves more 'feminine' (e.g. worried, nervous) and less 'masculine' (e.g. aggressive, cynical) traits. CONCLUSION: Sociopsychological variables of gender role orientation were related to chronic pain in the groups observed. An integrated model consisting of psychodynamic, sociological, and sociopsychological factors is proposed.     

Combined cytotoxic and anti-invasive properties of redox-active nanoparticles in tumor-stroma interactions

Tumor-stroma interaction plays an important role in tumor progression. Myofibroblasts, pivotal for tumor progression, populate the microecosystem of reactive stroma. The formation of myofibroblasts is mediated by tumor derived transforming growth factor β1 (TGFβ1) which initiates a reactive oxygen species cell type dependent expression of alpha-smooth muscle actin, a biomarker for myofibroblastic cells. Myofibroblasts express and secrete proinvasive factors significantly increasing the invasive capacity of tumor cells via paracrine mechanisms. Although antioxidants prevent myofibroblast formation, the same antioxidants increase the aggressive behavior of the tumor cells. In this study, the question was addressed of whether redox-active polymer-coated cerium oxide nanoparticles (CNP, nanoceria) affect myofibroblast formation, cell toxicity, and tumor invasion. Herein, nanoceria downregulate both the expression of alpha-smooth muscle actin positive myofibroblastic cells and the invasion of tumor cells. Furthermore, concentrations of nanoceria being non-toxic for normal (stromal) cells show a cytotoxic effect on squamous tumor cells. The treatment with redox-active CNP may form the basis for protection of stromal cells from the dominating influence of tumor cells in tumor-stroma interaction, thus being a promising strategy for chemoprevention of tumor invasion.     

Serum-Thyreoglobulinspiegel als Tumormarker bei Schilddrüsencarcinom

Zusammenfassung Um festzustellen, welche Wertigkeit der Thyreoglobulinmessung im Serum wegen differenzierten Schilddrüsencarcinoms thyreoidektomierter Patienten zukommt, wurde während der letzten 2 Jahre prospektiv der Verlauf der Thyreoglobulinspiegel (bis zu zwölfmal) bei 40 Patienten mit follikulärem oder papillärem Schilddrüsencarcinom nach Absetzen der Schilddrüsenhormongabe radioimmunologisch bestimmt und mit den Radiojodszintigrammen verglichen. In jeder Serumprobe wurden auch die Thyreoglobulinantikörper, ein möglicher Störfaktor der Thyreoglobulinbestimmung, radioimmunologisch gemessen.In der Mehrzahl der Fälle entsprachen Thyreoglobulinspiegel und Szintigramm einander, der Thyreoglobulinwert erlaubte aber eine exaktere Quantifizierung der Veränderungen der Tumormasse als die optische Beurteilung der Szintigramme. Bei einem der Patienten ergab die Szintigraphie einen völlig negativen, die Thyreoglobulinmessung hingegen einen deutlich positiven Befund: Bei diesem Patienten deckte die Röntgentomographie eine Lungenmetastase auf. Umgekehrt stellten sich bei Patienten ohne nachweisbares Thyreoglobulin radiojodspeichernde Metastasen im Szintigramm dar.Thyreoglobulin kann bei wegen differenzierten Schilddrüsencarcinoms thyreoidektomierten Patienten als Tumormarker betrachtet werden. Die Thyreoglobulinbestimmung kann jedoch nicht, wie es von einigen Autoren postuliert wurde, die Ganzkörperszintigraphie ersetzen, obwohl sie sich der Szintigraphie in manchen Fällen als überlegen erweist. Es empfiehlt sich daher die Kombination der Szintigraphie mit der Thyreoglobulinmessung für die Verlaufskontrolle von Patienten mit differenziertem Schilddrüsencarcinom.     

Ana o 2, a major cashew (Anacardium occidentale L.) nut allergen of the legumin family

BACKGROUND: We recently cloned and described a vicilin and showed it to be a major cashew allergen. Additional IgE-reactive cashew peptides of the legumin group and 2S albumin families have also been reported. Here, we attempt to clone, express and characterize a second major cashew allergen. METHODS: A cashew cDNA library was screened with human IgE and rabbit IgG anti-cashew extract antisera, and a reactive nonvicilin clone was sequenced and expressed as a fusion protein in Escherichia coli. Immunoblotting was used to screen for reactivity with patients' sera, and inhibition of immunoblotting was used to identify the corresponding native peptides in cashew nut extract. The identified allergen was subjected to linear epitope mapping using SPOTs solid-phase synthetic peptide technology. RESULTS: Sequence analysis showed the selected clone, designated Ana o 2, to encode for a member of the legumin family (an 11S globulin) of seed storage proteins. By IgE immunoblotting, 13 of 21 sera (62%) from cashew-allergic patients were reactive. Immunoblot inhibition data showed that the native Ana o 2 constitutes a major band at approximately 33 kD and a minor band at approximately 53 kD. Probing of overlapping synthetic peptides with pooled human cashew-allergic sera identified 22 reactive peptides, 7 of which gave strong signals. Several Ana o 2 epitopes were shown to overlap those of the peanut legumin group allergen, Ara h 3, in position but with little sequence similarity. Greater positional overlap and identity was observed between Ana o 2 and soybean glycinin epitopes. CONCLUSIONS: We conclude that this legumin-like protein is a major allergen in cashew nut.     

Differentiation of lymphocytes in cerebrospinal fluid in disorders of the central nervous system

Summary In 73 patients with variable CNS-disorders Slg-lymphocytes and RF-lymphocytes originating from CF were characterized by demonstration of surface markers. In the CF the Slg-lymphocytes were increased in comparison to the blood whereas the RF-lymphocytes generelly were decreased. Patients suffering from acute or chronic inflammatory diseases had significantly more Slg-lymphocytes while RF-lymphocytes were significantly decreased in those patients as well as in patients with malignancies. A correlation between the number of Slg-lymphocytes and immunoglobulin-levels was not seen. The respective data in blood did not follow the changes in CF. The results suggest a prevailing stimulation of the humoral immune system of the CNS during inflammatory diseases.     

Comparative evaluation of the Datex-Ohmeda S/5 Entropy Module and the Bispectral Index monitor during propofol-remifentanil anesthesia

BACKGROUND: Different analytical concepts were introduced to quantify the changes of the electroencephalogram. The Datex-Ohmeda S/5 Entropy Module (Datex-Ohmeda Division, Instrumentarium Corp., Helsinki, Finland) was the first commercial monitor based on the entropy generating two indices, the state entropy (SE) and the response entropy (RE). The aim of the current study was to compare the accuracy of SE and RE with the Bispectral Index(R) monitor (BIS(R); Aspect Medical Systems, Newton, MA) during propofol-remifentanil anesthesia. METHODS: The authors investigated 20 female patients during minor gynecologic surgery. SE, RE, BIS, mean arterial blood pressure, heart rate, and sedation level were recorded every 20 s during stepwise increase (target-controlled infusion, 0.5 microg/ml) of propofol until the patients lost response. Five minutes after loss of response, remifentanil infusion (0.4 microg . kg(-1) . min(-1)) was started. Spearman correlation coefficient and prediction probability were calculated for sedation levels with SE, RE, BIS, mean arterial blood pressure, and heart rate. The ability of the investigated parameters to distinguish between the anesthesia steps awake versus loss of response, awake versus anesthesia, anesthesia versus first reaction, and anesthesia versus extubation was analyzed with the prediction probability. RESULTS: SE correlates best with sedation levels, but no significant differences of the prediction probability values among SE, RE, and BIS were found. The prediction probability for all investigated steps of anesthesia did not show significant differences among SE, RE, and BIS. SE, RE, and BIS were superior to mean arterial blood pressure and heart rate. CONCLUSION: SE, RE, and BIS revealed similar information about the level of sedation and allowed the authors to distinguish between different steps of anesthesia. Both monitors provided useful additional information for the anesthesiologist.