An automatable platform for genotoxicity testing of nanomaterials based on the fluorometric γ-H2AX assay reveals no genotoxicity of properly surface-shielded cadmium-based quantum dots.

The large number of nanomaterial-based applications emerging in the materials and life sciences and the foreseeable increasing use of these materials require methods that evaluate and characterize the toxic potential of these nanomaterials to keep safety risks to people and environment as low as possible. As nanomaterial toxicity is influenced by a variety of parameters like size, shape, chemical composition, and surface chemistry, high throughput screening (HTS) platforms are recommended for assessing cytotoxicity. Such platforms are not yet available for genotoxicity testing. Here, we present first results obtained for application-relevant nanomaterials using an automatable genotoxicity platform that relies on the quantification of the phosphorylated histone H2AX (γ-H2AX) for detecting DNA double strand breaks (DSBs) and the automated microscope system AKLIDES® for measuring integral fluorescence intensities at different excitation wavelengths. This platform is used to test the genotoxic potential of 30 nm-sized citrate-stabilized gold nanoparticles (Au-NPs) as well as micellar encapsulated iron oxide nanoparticles (FeOx-NPs) and different cadmium (Cd)-based semiconductor quantum dots (QDs), thereby also searching for positive and negative controls as reference materials. In addition, the influence of the QD shell composition on the genotoxic potential of these Cd-based QDs was studied, using CdSe cores as well as CdSe/CdS core/shell and CdSe/CdS/ZnS core/shell/shell QDs. Our results clearly revealed the genotoxicity of the Au-NPs and its absence in the FeOx-NPs. The genotoxicity of the Cd-QDs correlates with the shielding of their Cd-containing core, with the core/shell/shell architecture preventing genotoxicity risks. The fact that none of these nanomaterials showed cytotoxicity at the chosen particle concentrations in a conventional cell viability assay underlines the importance of genotoxicity studies to assess the hazardous potential of nanomaterials.

Excitation wavelength dependence of the photoluminescence quantum yield and decay behavior of CdSe/CdS quantum dot/quantum rods with different aspect ratios.

The excitation wavelength (λexc) dependence of the photoluminescence (PL) quantum yield (ΦPL) and decay behavior (τPL) of a series of CdSe/CdS quantum dot/quantum rods (QDQRs), consisting of the same spherical CdSe core and rod-shaped CdS shells, with aspect ratios ranging from 2 to 20 was characterized. λexc between 400-565 nm were chosen to cover the first excitonic absorption band of the CdSe core material, the onset of absorption of the CdS shell, and the region of predominant shell absorption. A strong λexc dependence of relative and absolutely measured ΦPL and τPL was found particularly for the longer QDQRs with higher aspect ratios. This is attributed to combined contributions from a length-dependent shell-to-core exciton localization efficiency, an increasing number of defect states within the shell for the longest QDQRs, and probably also the presence of absorbing, yet non-emitting shell material. Although the ΦPL values of the QDQRs decrease at shorter wavelength, the extremely high extinction coefficients introduced by the shell outweigh this effect, leading to significantly higher brightness values at wavelengths below the absorption onset of the CdS shell compared with direct excitation of the CdSe cores. Moreover, our results present also an interesting example for the comparability of absolutely measured ΦPL using an integrating sphere setup and ΦPL values measured relative to common ΦPL standards, and underline the need for a correction for particle scattering for QDQRs with high aspect ratios.

Critical review of the determination of photoluminescence quantum yields of luminescent reporters.

A crucial variable for methodical performance evaluation and comparison of luminescent reporters is the photoluminescence quantum yield (Φ pl). This quantity, defined as the number of emitted photons per number of absorbed photons, is the direct measure of the efficiency of the conversion of absorbed photons into emitted light for small organic dyes, fluorescent proteins, metal-ligand complexes, metal clusters, polymeric nanoparticles, and semiconductor and up-conversion nanocrystals. Φ pl determines the sensitivity for the detection of a specific analyte from the chromophore perspective, together with its molar-absorption coefficient at the excitation wavelength. In this review we discuss different optical and photothermal methods for measuring Φ pl of transparent and scattering systems for the most common classes of luminescent reporters, and critically evaluate their potential and limitations. In addition, reporter-specific effects and sources of uncertainty are addressed. The ultimate objective is to provide users of fluorescence techniques with validated tools for the determination of Φ pl, including a series of Φ pl standards for the ultraviolet, visible, and near-infrared regions, and to enable better judgment of the reliability of literature data.

[S3 guidelines on diagnostics and therapy of bipolar disorders: development process and essential recommendations]. / S3-Leitlinie zur Diagnostik und Therapie bipolarer Störungen: Entwicklungsprozess und wesentliche Empfehlungen.

Bipolar disorders are severe psychiatric disorders with extensive individual and health economic consequences. Starting in 2007 the first German evidence and consensus based guideline for diagnostics and treatment of bipolar disorders was developed which holds the potential of increasing confidence of therapists, patients and relatives in the decision-making process and improving healthcare service experiences of patients and relatives. Apart from recommendations for diagnostics and treatment the guidelines provide those for trialogue action, knowledge transfer and self-help and for strategies for healthcare provision of this complex disorder. In the present article the methodology and essential recommendations are outlined and complemented in specific topics by corresponding articles in this special issue. Due to restrictions of the length of this presentation there is the need to refer to the comprehensive version of the guidelines at several points also regarding a detailed discussion of the limitations.

[Guideline on bipolar disorders and the importance of trialogue: chances and risks]. / Leitlinie Bipolare Störungen und die Bedeutung des Trialogs : Chancen und Risiken.

The term trialogue means the best possible equally contributing cooperation between affected patients and therapists as well as the self-evident inclusion of relatives. This is true for therapy, antistigma efforts by the planning of care, in associations such as the German Society for Bipolar Disorders and by assimilation of guidelines. Trialogue has a history and in its current version many levels and a hopeful vision of characteristics of understanding and treatment. This idea is presented here and relationships with characteristics of understanding and therapy of bipolar disorders will be made. Finally the recommendations of guidelines on trialogue will be presented and essential headings will be discussed under the aspect of trialogue: where and how are basic ideas and core demands of associations of affected persons and relatives considered? How is the process of trialogue to be assessed for the assimilation of guidelines? What are the chances and risks for the implementation? How can trialogue support the implementation?

A randomized study comparing interferon (IFN alpha) plus low-dose cytarabine and interferon plus hydroxyurea (HU) in early chronic-phase chronic myeloid leukemia (CML).

This multicenter randomized phase III study was designed to compare the efficacy and toxicity of IFN alpha-2c (3.5 MU/d) in combination with either araC (10 mg/m(2) d1-10) or hydroxyurea (HU: 25 mg/kg per day) in newly diagnosed CML patients. A total of 114 patients were randomized. Following a median observation period of 36 (range 1-73) months the major cytogenetic response rates were 25 and 27% and the 4-year survival probabilities 62.5 and 63% for the araC and HU group, respectively. While the overall toxicity profile was comparable between both groups, patients in the HU arm exhibited a slightly higher degree of WHO grades 3 and 4 non-hematological toxicities.

Chemometric modelling based on 2D-fluorescence spectra without a calibration measurement.

MOTIVATION: 2D fluorescence spectra provide information from intracellular compounds. Fluorophores like trytophan, tyrosine and phenylalanin as well as NADH and flavins make the corresponding measurement systems very important for bioprocess supervision and control. The evaluation is usually based on chemometric modelling using for their calibration procedure off-line measurements of the desired process variables. Due to the data driven approach lots of off-line measurements are required. Here a methodology is presented, which enables to perform a calibration procedure of chemometric models without any further measurement. RESULTS: The necessary information for the calibration procedure is provided by means of the a priori knowledge about the process, i.e. a mathematical model, whose model parameters are estimated during the calibration procedure, as well as the fact that the substrate should be consumed at the end of the process run. The new methodology for chemometric calibration is applied for a batch cultivation of aerobically grown S. cerevisiae on the glucose Schatzmann medium. As will be presented the chemometric models, which are determined by this method, can be used for prediction during new process runs. AVAILABILITY: The MATHLAB routine is free available on request from the authors.

Dose escalation of ara-c may improve response rates in a subgroup of chronic myeloid leukemia patients with poor response to interferon-alpha and low-dose ara-C.

The present analysis was performed to evaluate the impact of cytosine arabinoside (ara-C) dose escalation on hematological and cytogenetic responses in patients with chronic myelogenous leukemia (CML) who failed to respond to low-dose ara-C (LD ara-C) at a dose of 10 mg/m2/d over 10 days per month and interferon-alpha (IFNalpha, 3.5 MU/d). Following the same administration schedule, dose escalation of ara-C to 15 and 20 mg/m2/d 1-10 was performed in 36 of 119 patients (30%) due to inadequate hematological response and/or disease progression. As a result, improvement of hematological and cytogenetic responses was achieved in 22 (61%) and nine (25%) patients, respectively. Escalated ara-C dose levels were usually well tolerated, although some patients experienced deterioration of preexisting side effects. Our results support the critical role of ara-C dose towards a better disease control in CML.

Treatment of severe clozapine-induced neutropenia with granulocyte colony-stimulating factor (G-CSF). Remission despite continuous treatment with clozapine.

BACKGROUND: A 17-year-old boy suffering from a severe schizophrenic disorder of the paranoid type and mental retardation did not respond to treatment with typical antipsychotics, whereas under clozapine treatment he showed a favourable response. Discontinuation of clozapine led to an acute psychotic relapse. During clozapine treatment the patient developed severe neutropenia. METHOD AND RESULTS: Due to the history of unsatisfactory response to traditional antipsychotics, clozapine treatment was continued despite white blood cell (WBC) decline. Concomitant treatment with G-CSF was followed by a rapid normalisation of WBC. CONCLUSIONS: This case report is not intended to challenge the clinical practice of discontinuing clozapine upon the development of neutropenia/agranulocytosis, but rather to stimulate further research in the pathophysiology and clinical consequences of a clozapine rechallenge after a WBC decline, especially in patients with a rather complex symptomatology where no sufficient therapeutic results can be achieved with any other pharmacological intervention than clozapine.

Granulocyte colony-stimulating factor as an adjunct to induction chemotherapy for adult acute lymphoblastic leukemia--a randomized phase-III study.

Because of the recommendation to avoid the concomitant administration of growth factors and chemotherapy, there is only limited information on colony-stimulating factor (CSF) therapy in acute lymphoblastic leukemia (ALL) induction protocols, in which cytotoxic drugs are administered in divided doses over a prolonged period of time, thus requiring a simultaneous administration of growth factors and chemotherapy. We conducted a prospective, randomized, controlled study to determine the safety and efficacy of granulocyte colony-stimulating factor (G-CSF; filgrastim) as an adjunct to phase I of induction chemotherapy for adult ALL. Patients (n = 53) were randomized to receive no growth factor or G-CSF (5 microg/kg/d subcutaneously) starting on day 2 of chemotherapy consisting of daunorubicin (45 mg/m2) and vincristine (1.5 mg/m2) on days 1, 8, 15, and 22; L-asparaginase (2500 U/m2) on days 1 through 14; and prednisone (60 mg/m2) on days 1 through 28. A total of 25 patients in the G-CSF group and 26 patients in the control arm fulfilled the inclusion criteria of the study. G-CSF markedly ameliorated neutropenia because the median proportion of days with neutropenia less than 1,000/microL was 29% in the G-CSF group as compared with 84% in the control arm (P < .00005). The median time to reach absolute neutrophil counts (ANC) > or = 1,000/microL was 16 days in G-CSF patients and 26 days in controls (P < .001). More importantly, G-CSF significantly reduced the incidence of febrile neutropenia (12% v 42% in controls, P < .05) and documented infections (40% v 77%, P < .05). No significant differences were found with regard to requirements for red blood cell transfusions and platelet concentrates. A total of 24 of 25 (96%) patients in the G-CSF group and 20 of 25 (80%) evaluable control patients had complete remission after phase I of induction therapy. We conclude that G-CSF can be safely administered as an adjunct to induction therapy of ALL and is clinically beneficial by ameliorating neutropenia and reducing infectious complications.

Intraarticular morphine analgesia in chronic pain patients with osteoarthritis.

Controlled clinical studies have shown that local administration of morphine can significantly relieve acute postoperative pain. This analgesic effect is long-lasting (up to 48 h) and is mediated by peripheral opioid receptors. Experimental evidence shows that analgesic effects of peripheral opioids and the density of opioid receptors on peripheral sensory nerves increase with the duration of painful inflammatory processes. This study examines the analgesic effects of 1 mg of morphine injected into the arthritic knee joints of two groups of chronic pain patients (n = 23) suffering from osteoarthritis. Using a randomized, double-blind cross-over design, patients received either an intraarticular injection of morphine and intravenous saline (Group A, n = 13) or an intraarticular injection of saline and intravenous morphine (Group B, n = 10) during Phase I. Seven days later, patients crossed over to the opposite treatment (Phase II). During Phase I, intraarticular morphine resulted in significantly greater pain relief than intraarticular saline, and this effect was present at rest as well as during movement. The analgesic effect was surprisingly long-lasting and extended into Phase II, a carry-over effect that prevented the analysis of Phase II. No side effects were reported. The treatment of arthritic pain by peripherally acting opioids may be a promising alternative to currently available medications that have serious side effects.

Interferon-alpha-2C and LD ara-C for the treatment of patients with CML: results of the Austrian multi-center phase II study.

Small pilot studies of patients with CML have reported on encouraging response rates after treatment with interferon-alpha (IFNalpha) in combination with low-dose cytosine arabinoside (LD ara-C). We therefore initiated a multi-center phase II trial in order to investigate the efficacy and tolerability of this combination in newly diagnosed patients with Ph-positive chronic myelogenous leukemia (CML). Eighty-four patients were treated with IFN-alpha-2c at daily subcutaneous doses of 3.5 MU and LD ara-C added subcutaneously for 10 days every month at a dose of 10 mg/m2, following an initial reduction of WBC to less than 20 x 10(9)/l with hydroxyurea (HU). Within a median observation period of 28 (5-59) months the patients received a median of 7 (1-35) IFNalpha and LD ara-C cycles. Treatment was stopped due to side effects in 16 cases (19%) and to primary or secondary treatment failure in 38 cases (45%). In 45 patients (54%) complete hematological response (CHR) was achieved; in 39 patients (46%) cytogenetic responses including 15 (18%) complete cytogenetic responses (CHR) were observed. Median duration of cytogenetic responses was 15 months. Relapses were seen in 8/15 patients (53%) with complete cytogenetic remission (CCR), in 3/6 patients (50%) with partial cytogenetic response and in 9/18 patients (50%) with minor cytogenetic response. In conclusion, the combination of IFNalpha and LD ara-C resulted in encouraging rates of hematological and cytogenetic responses in patients with CML with low to moderate toxicity.

In vitro stimulation of erythropoiesis by stem cell factor alone in myelodysplastic syndrome patients with elevated endogenous erythropoietin serum levels.

Anemia remains a therapeutic problem in patients with myelodysplastic syndrome (MDS). In view of the recently reported potential of stem cell factor (SCF) in restoring erythropoiesis in combination with erythropoietin (Epo), we first aimed to define a correlation between SCF serum levels and anemia in MDS. Endogenous SCF levels in 50 MDS patients were determined by using a quantitative sandwich enzyme immunoassay. Broad interindividual variations were observed, but SCF serum levels were in the normal range with no correlation to peripheral blood count. A soft agar culture system was used to further define the role of SCF for stimulation of erythroid growth. Bone marrow mononucleated cells of 20 MDS patients (4 refractory anemia, 5 refractory anemia with excess of blasts, 7 refractory anemia with excess of blasts in transition, and 4 chronic myelomonocytic leukemia) were investigated, and SCF plus Epo was able to stimulate burst-forming unit-erythroid significantly more than SCF or Epo alone independent of French-American-British group. When mononucleated cells from six MDS patients (two refractory anemia, two refractory anemia with excess of blasts, and 2 refractory anemia with excess of blasts in transition) with elevated serum Epo levels were incubated in the presence of SCF and autologous serum, a significant dose-dependent stimulation of burst-forming unit-erythroid number and cells per colony was detected. Erythroid differentiation was further enhanced by adding serum with high colony-stimulating activity obtained from patients with severe aplastic anemia. Our data suggest that in MDS patients with high endogenous Epo serum levels SCF alone might be effective in stimulating erythropoiesis in vivo.

Hepatitis A in Western Austria--the epidemiological situation before the introduction of active immunisation.

Several European countries report a decreasing prevalence of antibodies to hepatitis A virus (anti-HAV). This trend is most pronounced in the youngest age groups. In 1979, however, 58% of young Austrians aged 20 to 30 years were shown to possess anti-HAV. Here we describe the current epidemiological situation in western Austria. Prevalence of anti-HAV has decreased to 7% in those 18 to 30 years old. This percentage rises to 20% (31 to 40 years of age) and 57% (41 to 50 years of age) and is highest in those older than 50 years (87%). Of 180 cases of clinical hepatitis A occurring from 1985 to 1992 45% were imported by travel to HAV-endemic areas. Seventy-one percent of the cases in children (59/83) occurred in foreign workers' families and were also predominantly acquired abroad. A change in prevention policy should be considered in this respect, as vaccination is available now.

Effects of clozapine on hematopoiesis and the cytokine system.

Using a bioassay for hematopoietic progenitor cells we looked for mechanisms causing clozapine induced neutropenia and agranulocytosis. Micro-agar-cultures of normal peripheral blood mononuclear cells (MNC) of eight patients currently treated with clozapine and of eight probands not receiving any kind of pharmacological treatment were incubated with increasing concentrations of clozapine (0, 7.5, 15, 30 micrograms/ml). Erythropoiesis and megakaryopoiesis were totally unaffected by clozapine. A biologically relevant suppression of granulopoiesis (CFU-GM) could only be shown in cultures incubated with 30 micrograms/ml clozapine. Cytokine analysis presented a strictly dose-dependent suppression of GM-CSF and neopterin release in all cultures. There was no difference between patients and controls at any clozapine concentration. The data support a possible role for cytokines as one mediator of the agranulocytosis producing effects of clozapine.

Pilot study of natural human interleukin-2 in patients with chronic hepatitis B. Immunomodulatory and antiviral effects.

Ten patients with chronic hepatitis B received increasing doses of nIL-2 (30,000 U, 100,000 U, 300,000 U, 1.0 million U) subcutaneously in a phase I trial. Each dose was applied once per week over 3 weeks. Serum samples were taken before and 2, 12, 24, 48 and 72 h after the first application of each dose level. Serum concentrations of interleukin-1 (IL-1), IL-2, IL-6, interferon-alfa (IFN-alpha), IFN-gamma, tumor necrosis factor-alpha (TNF-alpha) and GM-CSF as well as the cytokine-dependent serum components neopterin, beta-2-microglobulin (B2M), C-reactive protein (CPR), soluble IL-2-receptor (sIL-2R) and 2'-5'-oligoadenylate synthetase (2-5 OA) were assayed using ELISAs and RIAs. None of the samples tested contained measurable cytokine levels other than IL-2. A low and non-toxic dose of 300,000 U nIL-2 was already biologically active with induction of neopterin, B2M and sIL-2R. Dose-dependent changes peaked 24-48 h after application. The same patients were then enrolled in a phase II trial. Treatment in five of the patients was continued twice per week for 3 months with a biologically active dose of 300,000 U nIL-2 subcutaneously. Two of these patients as well as another five patients from the original group were treated with 1.0 million U nIL-2 subcutaneously, twice weekly for 3 months. Neither a biologically active but non-toxic dose of 300,000 U nIL-2, nor a toxic dose of 1.0 million U resulted in permanent clearance of hepatitis B early antigen (HBeAg).(ABSTRACT TRUNCATED AT 250 WORDS)

Recombinant human interleukin-8 restores function in neutrophils from patients with myelodysplastic syndromes without stimulating myeloid progenitor cells.

Prognosis in myelodysplastic syndrome (MDS) is not only correlated closely with blast cell count in bone marrow and chromosomal abnormalities but also correlated with decreased leucocyte count and function leading to acquisition of lethal infections. Recently, clinical trials in MDS have focused on the application of haemopoietic growth factors such as G-CSF or GM-CSF, which have proven to increase neutrophil count and function. However, these cytokines carry the risk of stimulating the malignant clone, particularly in patients with increased blast cell count. Therefore, investigation of cytokines which are able to stimulate neutrophil function without the potential risk of stimulating haemopoietic progenitor cells may be relevant for MDS. As the stimulatory effect of interleukin-8 on neutrophil function is well known, we investigated whether recombinant human IL-8 is also able to improve the function of neutrophils gained from patients with MDS. Using three different techniques--the E. coli killing assay (8 patients), the production of reactive oxygen as determined by cytochrome c reduction (7 patients) and chemiluminescence (8 patients)--a significant stimulation of neutrophil function at a concentration of 10 nm IL-8 was found in all test systems. No correlation with FAB classification was evident. On the other hand, IL-8 only mildly stimulated growth of myeloid progenitor cells in bone marrow culture of healthy individuals and MDS patients. This minimal stimulation was blocked by a neutralizing antibody directed against GM-CSF, suggesting an indirect effect of IL-8 via secondary GM-CSF release. Thus, IL-8 is able in vitro to repair the functional abnormalities of neutrophils from patients with MDS but has only a marginal influence on myeloid progenitor cells.

Detection of soluble IL-2 receptor in the serum of patients with myelodysplastic syndromes: induction under therapy with GM-CSF.

Sera of 15 healthy controls and 33 patients suffering from myelodysplastic syndromes (MDS) were investigated for soluble interleukin-2 receptor (sIL-2R) expression with a cell-free enzyme-linked immunosorbent assay (ELISA) system (T-Cell Sciences; Cambridge, U.S.A.). The upper limit of the assay is indicated with 477 U/ml. According to the FAB classification eight refractory anaemia (RA), 15 refractory anaemia with excess of blasts (RAEB), five refractory anaemia with excess blasts in transformation (RAEBt) and five chronic myelomonocytic leukaemia (CMML) were examined. None of the patients had reported infectious episodes or been under treatment with cytotoxic agents and/or cytokines within the previous 3 months. Significant differences in sIL-2R levels between RA (median 368 U/ml). RAEB (median 675 U/ml) and RAEBt (median 971 U/ml) and between RA and CMML (median 723 U/ml) were detected. Six patients, who had been under treatment with rhGM-CSF for at least 2 weeks, demonstrated a three- to sevenfold increase of sIL-2R expression compared to pretreatment levels. In kinetic evaluation of serum samples for 24 h, the increase of sIL-2R expression begins within 4 h after subcutaneous application of GM-CSF and reaches its maximum after 12 h. Our data cannot suggest whether increased sIL-2R expression is a primary event due to involvement of lymphocytes in the malignant clone or whether it results from secondary alteration of the cytokine network. Application of GM-CSF in MDS may result in improvement of altered lymphocyte function. As GM-CSF induces sIL-2R expression, a down regulation of the immune response caused by neutralization of free IL-2 cannot be excluded.

Priming of normal human neutrophils by tachykinins: tuftsin-like inhibition of in vitro chemotaxis stimulated by formylpeptide or interleukin-8.

Tachykinins have priming effects on polymorphonuclear neutrophils, since they may activate the neutrophils to exhibit an exaggerated inflammatory response to phlogistic mediators. In order to investigate mechanisms involved in this action, we determined the influence of substance P and neurokinin A on chemotaxis of human neutrophils towards gradients of formymethionyl-leucyl-phenylalanine or recombinant human interleukin-8. As seen with other neutrophil-priming agents such as tumor necrosis factor-alpha, exposure of neutrophils to substance P or neurokinin A had an inhibitory effect upon a stimulated migration, with effective concentrations being in the nanomolar range. Tuftsin, a known neutrophil activating peptide, similarly inhibited stimulated migration. Analysis of structure-activity relationships revealed that activity of tachykinins is located in amino-terminal, tuftsin-like sequences. The inhibition of stimulated migration was partly reversed by (Pro1)-tuftsin, a partial tuftsin receptor antagonist, which suggests that the effects of amino-terminal tachykinins involves activation of tuftsin receptors of neutrophils.