Excellent translational research in oncology: A journey towards novel and more effective anti-cancer therapies.

Comprehensive Cancer Centres (CCCs) serve as critical drivers for improving cancer survival. In Europe, we have developed an Excellence Designation System (EDS) consisting of criteria to assess "excellence" of CCCs in translational research (bench to bedside and back), with the expectation that many European CCCs will aspire to this status.

Many-body dynamics of exciton creation in a quantum dot by optical absorption: a quantum quench towards Kondo correlations.

We study a quantum quench for a semiconductor quantum dot coupled to a fermionic reservoir, induced by the sudden creation of an exciton via optical absorption. The subsequent emergence of correlations between spin degrees of freedom of dot and reservoir, culminating in the Kondo effect, can be read off from the absorption line shape and understood in terms of the three fixed points of the single-impurity Anderson model. At low temperatures the line shape is dominated by a power-law singularity, with an exponent that depends on gate voltage and, in a universal, asymmetric fashion, on magnetic field, indicative of a tunable Anderson orthogonality catastrophe.

Investigator-initiated trials of targeted oncology agents: why independent research is at risk?

BACKGROUND: Drug development traditionally has relied upon the complementary contributions of clinicians and scientists at academic institutions and at pharmaceutical companies. Greater regulatory burdens, increased bureaucratic requirements, restricted reimbursement, and spiralling research and development costs are exerting pressure on the drug development pipeline. The result is a de-emphasis of exploratory research, particularly independent academic research, despite its proven value in identifying new drug targets and developing innovative cancer therapies. DESIGN: An expert panel assembled by the Biotherapy Development Association-a nonprofit international forum for academic and industry researchers, patients, and government regulatory and postregulatory agencies-examined the growing schism between academia and industry and identified several causes of declining academic research. RESULTS: The authors propose solutions to sustain investigator-initiated research and provide a new model whereby expert organisations provide a forum for academia and industry to plan studies within a regulatory framework to support licensure/authorisation and reimbursement for new molecularly targeted agents and biomarkers. CONCLUSIONS: Investigator-initiated trials have led to the discovery and development of innovative, safe, and effective cancer treatments. To ensure that such research continues, action will be required on the parts of legislative and regulatory bodies, industry, universities, patient advocacy organisations, and preclinical and clinical academic scientists.

Quantum criticality perspective on the charging of narrow quantum-dot levels.

Understanding the charging of exceptionally narrow levels in quantum dots in the presence of interactions remains a challenge within mesoscopic physics. We address this fundamental question in the generic model of a narrow level capacitively coupled to a broad one. Using bosonization we show that for arbitrary capacitive coupling charging can be described by an analogy to the magnetization in the anisotropic Kondo model, featuring a low-energy crossover scale that depends in a power-law fashion on the tunneling amplitude to the level. Explicit analytical expressions for the exponent are derived and confirmed by detailed numerical and functional renormalization-group calculations.

Numerical renormalization group calculation of near-gap peaks in spectral functions of the Anderson model with superconducting leads.

We use the numerical renormalization group method (NRG) to investigate a single-impurity Anderson model with a coupling of the impurity to a superconducting host. Analysis of the energy flow shows that, contrary to previous belief, NRG iterations can be performed up to a large number of sites, corresponding to energy differences far below the superconducting gap Δ. This allows us to calculate the impurity spectral function A(ω) very accurately for frequencies |ω|∼Δ, and to resolve, in a certain parameter regime, sharp peaks in A(ω) close to the gap edge.

Mesoscopic to universal crossover of the transmission phase of multilevel quantum dots.

Transmission phase alpha measurements of many-electron quantum dots (small mean level spacing delta) revealed universal phase lapses by pi between consecutive resonances. In contrast, for dots with only a few electrons (large delta), the appearance or not of a phase lapse depends on the dot parameters. We show that a model of a multilevel quantum dot with local Coulomb interactions and arbitrary level-lead couplings reproduces the generic features of the observed behavior. The universal behavior of alpha for small delta follows from Fano-type antiresonances of the renormalized single-particle levels.

Competition for attachment of aquaculture candidate probiotic and pathogenic bacteria on fish intestinal mucus.

Probiotics for aquaculture are generally only selected by their ability to produce antimicrobial metabolites; however, attachment to intestinal mucus is important in order to remain within the gut of its host. Five candidate probiotics (AP1-AP5), isolated from the clownfish, Amphiprion percula (Lacepéde), were examined for their ability to attach to fish intestinal mucus and compete with two pathogens, Aeromonas hydrophila and Vibrio alginolyticus. Two different radioactive isotopes were used to quantify competition between pathogens and probionts. Attachment of the pathogens was enhanced by the presence of the candidate probiotics. However, the addition of the candidate probiotics after the pathogens resulted in reduced pathogen attachment. Only AP5 caused lower attachment success of V. alginolyticus when added before the pathogen. When AP5 was added first, the average attachment change was 41% compared with 72% when added after V. alginolyticus, suggesting that the probiotic is displaced but that enhanced attachment of the pathogen does not occur. Conversely, when V. alginolyticus was added first, followed by AP5, attachment change was 37% while AP5 had 92% attachment change when added second. This implies that the pathogen was displaced by the candidate probiotic and therefore it appeared that, based on the ability of probiont AP5 to attach to mucus, the growth of the pathogen in the digestive tract might be suppressed by the candidate probiont's presence.

Role of the 2D surface state continuum and projected band gap in charge transfer in front of a Cu(111) surface

Electron capture by Li+ and H projectiles in grazing scattering from Cu(111) and Cu(110) surfaces is studied experimentally and theoretically. Whereas data for Cu(110) can be described by established theoretical methods treating resonant charge transfer with a free-electron metal, data for Cu(111) show pronounced deviations from this approach. We interpret our observations by the effect of the projected L-band gap of the Cu(111) surface. In particular, the quantum states of reduced dimension (2D surface state continuum) play a dominant role in electron transfer.

Effect of the projected band gap on the formation of negative ions in grazing collisions from Cu surfaces.

The formation of negative ions (H-, O-, S-, F-, Cl-) is studied for grazing scattering of fast ions from Cu(110) and Cu(111) surfaces. In a detailed experimental and theoretical investigation we reveal that the projected L-band gap of the Cu metal affects charge transfer in a specific manner. From the analysis of the negative ion fractions as functions of projectile velocity we conclude that, for the Cu(111) surface the electronic 2D surface state continuum plays an essential role in the projectile-surface electron transfer.

High levels of thrombopoietin in sera of patients with essential thrombocythemia: cause or consequence of abnormal platelet production?

Thrombopoietin (TPO) is the most important regulator of megakaryocyte development and platelet production. Platelet production is thought to be regulated by a negative regulatory feed back loop. In an attempt to evaluate the role of TPO in the pathobiology of essential thrombocythemia (ET), we have examined levels of TPO and other cytokines with thrombopoietic activity (interleukin-6 and interleukin-11) in sera obtained from 25 patients with ET (ten treated, 15 untreated) and 117 healthy control subjects. TPO serum levels were assessed using a sandwich-antibody ELISA that utilizes a polyclonal rabbit antiserum for both capture and signal. The mean serum TPO level in 25 ET patients was significantly elevated (545+/-853 pg/ml) as compared with that in healthy controls (95.3+/-54.0 pg/ml,p<0.001). The difference in TPO serum levels between ten treated (781+/-1229 pg/ ml) and 15 untreated ET patients (388+/-458 pg/ml) did not reach statistical significance (p = 0.09). We conclude that either consumption or production of TPO is altered in ET. Failure of appropriate feedback regulation and continued megakaryocyte stimulation by an elevated TPO may play an important role in the pathobiology of ET.

Thrombopoietin serum levels in patients with aplastic anaemia: correlation with platelet count and persistent elevation in remission.

In an attempt to evaluate the role of thrombopoietin (TPO) in the pathobiology of aplastic anaemia (AA), we have examined TPO levels in sera from 54 AA patients and 119 healthy controls. A total of 92 samples were collected from AA patients: 43 samples were harvested at diagnosis, 23 samples in the cytopenic period after treatment, and 26 samples when patients were in partial (n=10) or complete remission (n=16) following immunosuppressive treatment. TPO serum levels were assessed by a sandwich-antibody ELISA that utilized a polyclonal rabbit antiserum for both capture and signal. Serum samples from normal donors revealed a mean TPO level of 95.3 +/- 54.0 pg/ml (standard deviation). Mean TPO levels in AA sera collected at diagnosis and before onset of treatment were 2728 +/- 1074 pg/ml (P<0.001 compared to normal controls: mean platelet count at that time: 27x10(9)/l). TPO serum levels of AA patients in partial or complete remission after immunosuppressive treatment were significantly lower than TPO levels at diagnosis (P<0.001). However, despite normal platelet counts (mean 167x10(9)/l), TPO levels remained significantly elevated in complete remission (mean TPO 1009 +/- 590 pg/ml, P<0.001 compared to normal controls). There was a significant inverse correlation between serum TPO levels and platelet counts in AA patients who were not transfused for at least 2 weeks prior to sample collection (coefficient of correlation (r) = -0.70, P<0.0001). In summary, TPO levels were highly elevated in sera of patients with AA. Thus there is no evidence to suggest an impaired TPO response contributing to thrombocytopenia in AA. Thrombopoietin did not return to normal levels in remission, indicating a persisting haemopoietic defect in remission of AA. We hypothesize that elevated levels of TPO may be required to maintain normal or near normal platelet counts in remission of AA.

Influence of gelatin matrices cross-linked with transglutaminase on the properties of an enclosed bioactive material using beta-galactosidase as model system.

Transglutaminase (protein-glutamine: amine gamma-glutamyltransferase, EC 2.3.2.13) from Streptoverticillium mobaraense has been used to stabilize immobilisates produced with beta-galactosidase (beta-D-galactoside galactohydrolase, EC 3.2.1.23) from Aspergillus oryzae and acid-processed gelatins of different qualities as support. The isopeptide level of N epsilon-(gamma-L-glutamyl)-L-lysine bonds formed by transglutaminase was determined to estimate their influence on the kinetic properties of the enclosed beta-galactosidase. An HPLC procedure using precolumn derivatization of the gelatin hydrolysates with FMOC-chloride was chosen which permits the analysis of cross-linked lysine with satisfactory precision. Depending on the gelatin quality, the degree of cross-links necessary for the transformation of gelatin into an insoluble protein was in the range 0.3-32.3% of the available lysine residues. beta-Galactosidase was entrapped in the gelatin matrices with a yield of 8-46% of the initial activity. Long reaction times for cross-linking were due to low yields rather than to the number of isopeptide bonds. Repeated use of the immobilisates did not lead to an appreciable loss of activity. The Vmax of beta-galactosidase were diminished by immobilization caused by a tighter package of the protein chains rather than by the extent of cross-links, while the obtained Km values of the free enzyme and the immobilisates were quite similar. Also, the pH and temperature of optima of the free enzyme and the gelatin immobilisates differ only slightly. The data suggest that the immobilization procedure only moderately affects the activity of enzymes catalysing the reaction of a small compound if gelatin with high jelly strength is cross-linked in a 10% solution with transglutaminase.

Phase Ia trial of murine immunoglobulin A antitransferrin receptor antibody 42/6.

In preclinical in vitro and in vivo systems, mAbs to human transferrin (Tf) receptors blocked iron uptake from Tf and showed antitumor activity. However, Tf receptors are also displayed by normal tissues, and a large, soluble pool of circulating serum Tf receptors has been detected. We report results of a Phase Ia trial of IgA monoclonal anti-Tf receptor antibody 42/6. Twenty-seven patients with advanced refractory cancer received 33 treatments with 42/6 administered as a 24-h infusion at doses ranging from 2.5 to 300 mg/m2. 42/6 was generally well tolerated, although one patient receiving a second treatment experienced an allergic-type response associated with a human antimouse antibody response. Three patients with hematological cancers showed mixed tumor responses; there were no partial or complete remissions. Peak serum levels of antibody were obtained at the termination of the 24-h infusion. At doses >/=25 mg/m2, there was a linear relationship between the 42/6 dose and average peak serum 42/6 levels ranging from <1 to 36 microgram/ml. Serum Tf receptors showed a dose-dependent decrease during 42/6 infusion to 20-30% of baseline, and remained depressed for at least 48 h after terminating the infusion. Serum 42/6 levels rose in an inverse relationship to the drop in Tf receptors. 42/6 induced an increase in serum iron and Tf saturation consistent with blockade of peripheral iron uptake, and reduced Tf receptor display by bone marrow cells. Human antimouse antibody was detected in nine patients. Anti-Tf receptor antibody was well tolerated and mediated in vivo effects on iron uptake and Tf display. Antibody concentrations capable of inhibiting malignant blood cell growth were obtained without toxicity. This represents the first clinical trial of an IgA mouse mAb, and one of only a few trials in which an antibody reacting with a broad range of normal tissues has been administered. Additional clinical trials of anti-Tf receptor antibodies in blood cell cancers are indicated.

Results of a randomised, controlled, multicentre study of recombinant human granulocyte colony-stimulating factor (filgrastim) in patients with Hodgkin's disease and non-Hodgkin's lymphoma undergoing autologous bone marrow transplantation.

In 54 patients with malignant lymphoma, haematopoietic recovery after high-dose chemotherapy and autologous bone marrow transplantation (BMT) was compared between patients randomised to receive 10 or 30 micrograms/kg/day of r-metHuG-CSF (filgrastim) or no growth factor. After standard high-dose chemotherapy with cyclophosphamide, etoposide and BCNU (CVB regimen for patients with Hodgkin's disease) or BCNU, etoposide, cytosine arabinoside and melphalan (BEAM regimen for patients suffering from non-Hodgkin's lymphoma) followed by autologous BMT, r-metHuG-CSF was administered by continuous intravenous infusion from the first day after autologous BMT until neutrophil recovery. When the r-metHuG-CSF groups were compared with the control group the major findings were: the median time to reach an absolute neutrophil count (ANC) > or = 0.5 x 10(9)/L was 20 days in the control group and 12 and 14 days, respectively, in the r-metHuG-CSF groups (P = 0.0004). The duration of neutropenia (ANC < 0.5 x 10(9)/L) was reduced from 27 days in the control group to 11 and 13 days in the r-metHuG-CSF groups (P = 0.0001). In addition, fewer days of febrile neutropenia were observed in the r-metHuG-CSF groups (5 and 6 days) than in the control group (10 days; P = 0.036). No significant effects of r-metHuG-CSF administration on the number of days with fever, the use of intravenous antibiotics and hospitalisation were detected. R-metHuG-CSF was well tolerated without any serious side-effects.(ABSTRACT TRUNCATED AT 250 WORDS)

Peripheral blood progenitor cells mobilized by chemotherapy plus granulocyte-colony stimulating factor accelerate both neutrophil and platelet recovery after high-dose VP16, ifosfamide and cisplatin.

We report on the chemotherapy plus granulocyte colony-stimulating factor (G-CSF) induced mobilization of peripheral blood progenitor cells (PBPCs) and their impact on haematopoietic recovery following high-dose chemotherapy. Twenty-four patients with advanced solid tumours or lymphomas received standard-dose chemotherapy with VP16, ifosfamide and cisplatin (VIP) followed by filgrastim (G-CSF; 5 micrograms/kg s.c. daily for 14 d) for the prevention of chemotherapy induced neutropenia and for the simultaneous mobilization of PBPCs. Maximal numbers of progenitors of different lineages were reached at day 11 (range 9-14) after VIP chemotherapy. A median of 0.415 x 10(9)/l CD34+ cells (range 0.11-1.98), 9000 CFU-GM/ml (range 2800-17,700), 3500 BFU-E/ml (range 400-10,800) and 200 CFU-GEMM/ml (range 0-4400) were recruited. One single apheresis yielded a median of 1.6 x 10(8) mononuclear cells/kg (range 0.2-5.4) or 5.4 x 10(6) CD34+ cells/kg body weight (range 0.2-24.2). Fourteen patients who showed at least a partial remission after two cycles of the standard-dose chemotherapy regimen were subjected to high-dose VIP chemotherapy (cumulative doses of 1500 mg/m2 VP16, 12 g/m2 ifosfamide and 150 mg/m2 cisplatin) with or without PBPC support. The first six patients were treated with growth factors only (IL-3/GM-CSF) and did not receive PBPCs, whereas the following eight patients were supported with PBPCs in addition to IL-3 and GM-CSF. Neutrophil recovery as well as platelet recovery were significantly faster in patients receiving PBPCs with a median of 6.5 d below 0.1 x 10(9) neutrophils/l and 3 d below 20 x 10(9) platelets/l as compared to 10.5 d and 8 d in control patients receiving growth factors only. The accelerated platelet recovery in patients supported with PBPCs might be explained--in the absence of detectable colony-forming units megakaryocyte--by the presence of glycoprotein IIb/IIIa+, non-proliferating endomitotic megakaryocytic precursor cells within G-CSF mobilized PBPCs. Our data demonstrate that chemotherapy plus G-CSF mobilized PBPCs accelerate both neutrophil and platelet recovery after high-dose VIP chemotherapy in patients with solid tumours or lymphomas.

Hematopoietic growth factors in bone marrow transplantation.

Preliminary clinical results demonstrate the activity of recombinant human granulocyte (rHuG) and granulocyte/macrophage (rHuGM) colony stimulating factors (CSFs) in enhancing bone marrow engraftment after autologous and allogeneic bone marrow transplantation (BMT). In several analyses of prospective, controlled clinical trials of rHuG- and rHuGM-CSF, reduced morbidity and cost, as well as improved survival have been observed. There is reason to hope that more profound understanding of the in vivo biology of these and other cytokines will lead to further reduction in morbidity and mortality associated with both autologous as well as allogeneic BMT. These advances could significantly broaden the spectrum of diseases amenable to treatment by BMT.

Targeting human T-lymphocytes with bispecific antibodies to react against human ovarian carcinoma cells growing in nu/nu mice.

In the present study we tested whether human T-cells from normal donors can be targeted against human ovarian carcinoma cells and block i.p. growth of an established tumor in immunodeficient mice. For targeting we used chemically cross-linked bispecific monoclonal antibodies (mAbs) reacting with CD3 on the T-cells and with cell-surface antigens selectively expressed by tumor cells. The tumor model consisted of mice given i.p. injections of a human ovarian carcinoma cell line, OVCAR-3, whose growth includes development of massive ascites. Peripheral blood lymphocytes from normal human donors were cultured overnight with 50-100 units/ml recombinant interleukin 2, coated with bispecific antibodies, and injected i.p. into mice 4-6 days after tumor inoculation, at which time tumor cells were established and growing in about 85% of the hosts. Tumor growth was assessed by the number of tumor cells, and in some tests by cell-free tumor antigen, recovered in peritoneal lavage fluid collected 15 days after tumor priming. Treatment with lymphocytes retargeted with bispecific mAbs, prepared with anti-CD3 and three different antitumor mAbs, 113F1, OVB-3, and MOv19, gave highly significant increases in percentages of mice without detectable tumor. Controls showed that the antitumor activity of retargeted lymphocytes did not result simply from antibody-dependent cellular cytotoxicity or from heteroconjugates reacting only with CD3 or with lymphocyte major histocompatibility complex determinants and tumor cells. These results show that targeted T-lymphocytes can significantly decrease the growth of an established tumor in a fashion specific for antigens expressed by the neoplastic cells.