[Pelvic vein thrombosis : Current treatment options and importance of recanalization procedures]

Venous thrombosis is a frequent disorder. A distinction is made between an acute phase of the disease and a chronic manifestation, the postthrombotic syndrome. In particular, proximal venous thrombosis/pelvic vein thrombosis can cause a life-threatening pulmonary embolism during the acute phase of the disease. The postthrombotic syndrome is characterized by the remodeling of the affected venous section, which is often caused by inflammation. Locally, the typical clinical finding is caused by scarred stricture of the vein with restricted drainage and peripheral venous hypertension. Acute thrombosis should be primarily treated by therapeutic anticoagulation and compression therapy of the affected extremity. The duration of these measures depends on clinical presentation, cause (provoked, unprovoked) and risk factors for venous thrombosis/recurrent thrombosis. Venous revascularization procedures are important both in the acute phase of the disease and in the treatment of postthrombotic syndrome. The recanalization treatment is mostly carried out as an endovascular or hybrid intervention and venous bypass procedures are reserved for special situations.

Targeting GD2 after allogeneic SCT: effector cell composition defines the optimal use of ch14.18 and the bispecific antibody construct NG-CU (GD2-CD3)

We investigated whether T cell-recruiting bispecific anti-CD3/GD2 antibody NG-CU might be an alternative to therapeutic anti-GD2 monoclonal antibody (mAb) ch14.18, mediating complement-dependent cytotoxicity (CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC) through natural killer (NK) cells for immunotherapy in high-risk/relapsed neuroblastoma after autologous/allogeneic stem cell transplantation (auto/alloSCT). Different antibody concentrations and effector-to-target ratios (E:T) were evaluated using xCELLigence RTCA system, peripheral blood mononuclear cells (PBMCs) (healthy donors and patients after alloSCT), and neuroblastoma cell lines (LS/LAN-1). Mean specific lysis of LS cells utilizing PBMCs from healthy donors and ch14.18 (1 µg/ml) was 40/66/75% after 12/24/48 h compared to 66/93/100% in the presence of NG-CU (100 ng/ml). NG-CU showed enhanced cytotoxicity compared to ch14.18, even at lower concentrations and E:T ratios, and completely eradicated LS cells after 72 h. To decipher the influence of effector cell subsets on lysis, different ratios of T and NK cells were tested. At a ratio of 1:1, ch14.18 was more effective than NG-CU. Using patient PBMCs taken at different time points posttransplant, significant lysis with both constructs was detectable depending on percentages and total numbers of T and NK cells; in the early posttransplant phase, NK cells were predominant and ch14.18 was superior, whereas later on, T cells represented the majority of immune cells and NG-CU was more effective. Our study highlights the importance of analyzing effector cell subsets in patients before initiating antibody-based therapy. Consequently, we propose an adjusted administration of both antibody constructs, considering the state of posttransplant immune recovery, to optimize anti-tumor activity.

DK-MGAR101, an extract of adventitious roots of mountain ginseng, improves blood circulation by inhibiting endothelial cell injury, platelet aggregation, and thrombus formation

Background

Since ginsenosides exert an anti-thrombotic activity, blood flow-improving effects of DK-MGAR101, an extract of mountain ginseng adventitious roots (MGAR) containing various ginsenosides, were investigated in comparison with an extract of Korean Red Ginseng (ERG).

Methods

In Sprague-Dawley rats orally administered with DK-MGAR101 or ERG, oxidative carotid arterial thrombosis was induced with FeCl₃ (35%), and their blood flow and occlusion time were measured. To elucidate underlying mechanisms, the cytoprotective activities on rat aortic endothelial cells (RAOECs) exposed to hydrogen peroxide (H₂O₂) were confirmed. In addition, the inhibitory activities of DK-MGAR101 and ERG on agonist-induced platelet aggregation, thromboxane B₂ production, and ATP granule release from stimulated platelets as well as blood coagulation were analyzed.

Results

DK-MGAR101 containing high concentrations of Rb1, Rg1, Rg3, Rg5, and Rk1 ginsenosides (55.07 mg/g) was more effective than ERG (ginsenosides 8.45 mg/g) in protecting RAOECs against H₂O₂ cytotoxicity. DK-MGAR101 was superior to ERG not only in suppressing platelet aggregation, thromboxane B₂ production, and granule release, but also in delaying blood coagulation, FeCl₃-induced arterial occlusion, and thrombus formation.

Conclusions

The results indicate that DK-MGAR101 prevents blood vessel occlusion by suppressing platelet aggregation, thrombosis, and blood coagulation, in addition to endothelial cell injury.

Model reduction techniques for the computation of extended Markov parameterizations for generalized Langevin equations

The generalized Langevin equation is a model for the motion of coarse-grained particles where dissipative forces are represented by a memory term. The numerical realization of such a model requires the implementation of a stochastic delay-differential equation and the estimation of a corresponding memory kernel. Here we develop a new approach for computing a data-driven Markov model for the motion of the particles, given equidistant samples of their velocity autocorrelation function. Our method bypasses the determination of the underlying memory kernel by representing it via up to about twenty auxiliary variables. The algorithm is based on a sophisticated variant of the Prony method for exponential interpolation and employs the positive real lemma from model reduction theory to extract the associated Markov model. We demonstrate the potential of this approach for the test case of anomalous diffusion, where data are given analytically, and then apply our method to velocity autocorrelation data of molecular dynamics simulations of a colloid in a Lennard-Jones fluid. In both cases, the velocity autocorrelation function and the memory kernel can be reproduced very accurately. Moreover, we show that the algorithm can also handle input data with large statistical noise. We anticipate that it will be a very useful tool in future studies that involve dynamic coarse-graining of complex soft matter systems.

[The DIGG risk score : A risk predictive model of perioperative mortality after elective treatment of intact abdominal aortic aneurysms in the DIGG register]

OBJECTIVE

The aim of the study was to develop a specific risk score for the aortic register of the German Institute for Vascular Health Care Research (DIGG) of the German Society for Vascular Surgery and Vascular Medicine (DGG) for the prediction of postoperative mortality in elective treatment of intact abdominal aortic aneurysms (iAAA). The score should also enable a risk-adjusted presentation of the register results in the near future.

METHODS

The method of binary logistic regression analysis was used to calculate the model. The data from 10,404 patients were included in the analysis, of whom 7870 (75.6%) were treated by endovascular (EVAR) and 2534 (24.4%) by open (OR) aortic repair. It was examined which factors have an independent influence on hospital mortality and the effect size was determined as a score.

RESULTS

For EVAR, the influencing factors with their effect sizes (score in brackets) were: age >85 years (2), female gender (2), juxtarenal AAA (5), maximum diameter >65 mm (2), diabetes mellitus (2), American Society of Anesthesiologists (ASA) score >3 (2), cardiac comorbidities (3) and renal insufficiency stage >3 (5). For OR the factors were: age >80 years (2), female gender (2), juxtarenal AAA (2), ASA score >3 (3), previous myocardial infarction (2), renal comorbidities (3) and previous stroke (2). The estimated hospital mortality was calculated for the individual case from the sum of the risk factors (scores). The accuracy of the model (correlation between observed and expected results) was determined using the receiver operating characteristic (ROC) curve. An area under the curve (AUC) of 0.817 (confidence interval 0.789-0.844) demonstrated an excellent discrimination. In a validation group of 3831 patients, the good agreement between observed and calculated results was confirmed.

CONCLUSION

The DIGG risk score can predict risk-adjusted hospital mortality after EVAR and OR of iAAA in the DIGG register. Improvements with respect to the prediction are desirable for OR and should be strived for by extending the model in the future.

Tyrosine kinase inhibition increases the cell surface localization of FLT3-ITD and enhances FLT3-directed immunotherapy of acute myeloid leukemia

The fms-related tyrosine kinase 3 (FLT3) receptor has been extensively studied over the past two decades with regard to oncogenic alterations that do not only serve as prognostic markers but also as therapeutic targets in acute myeloid leukemia (AML). Internal tandem duplications (ITDs) became of special interest in this setting as they are associated with unfavorable prognosis. Because of sequence-dependent protein conformational changes FLT3-ITD tends to autophosphorylate and displays a constitutive intracellular localization. Here, we analyzed the effect of tyrosine kinase inhibitors (TKIs) on the localization of the FLT3 receptor and its mutants. TKI treatment increased the surface expression through upregulation of FLT3 and glycosylation of FLT3-ITD and FLT3-D835Y mutants. In T cell-mediated cytotoxicity (TCMC) assays, using a bispecific FLT3 × CD3 antibody construct, the combination with TKI treatment increased TCMC in the FLT3-ITD-positive AML cell lines MOLM-13 and MV4-11, patient-derived xenograft cells and primary patient samples. Our findings provide the basis for rational combination of TKI and FLT3-directed immunotherapy with potential benefit for FLT3-ITD-positive AML patients.

Blood flow-improving activity of methyl jasmonate-treated adventitious roots of mountain ginseng

Ginsenosides from Panax ginseng are well known for their diverse pharmacological effects including antithrombotic activity. Since adventitious roots of mountain ginseng (ARMG) also contain various ginsenosides, blood flow-improving effects of the dried powder and extract of ARMG were investigated. Rats were orally administered with dried powder (PARMG) or ethanol extract (EARMG) of ARMG (125, 250 or 500 mg/kg) or aspirin (30 mg/kg, a reference control) for 3 weeks. Forty min after the final administration, carotid arterial thrombosis was induced by applying a 70% FeCl3-soaked filter paper outside the arterial wall for 5 min, and the blood flow was monitored with a laser Doppler probe. Both PARMG and EARMG delayed the FeCl3-induced arterial occlusion in a dose-dependent manner, doubling the occlusion time at high doses. In mechanism studies, a high concentration of EARMG inhibited platelet aggregation induced by collagen in vitro. In addition, EARMG improved the blood lipid profiles, decreasing triglyceride and cholesterol levels. Although additional action mechanisms remain to be clarified, it is suggested that ARMG containing high amount of ginsenosides such as Rg3 improves blood flow not only by inhibiting oxidative thrombosis, but also by modifying blood lipid profiles.

Conductivity fluctuations in proton-implanted ZnO microwires

Electric noise can be an important limitation for applications of conducting elements in the nanometer size range. The intrinsic electrical noise of prospective materials for opto-spintronics applications like ZnO has not yet been characterized. In this study, we have investigated the conductivity fluctuations in 10 nm thick current paths produced by proton implantation of ZnO microwires at room temperature. The voltage noise under a constant dc current bias in undoped, as well as in Li-doped microwires, is characterized by [Formula: see text] power spectra with [Formula: see text]. The noise intensity scales with the square of the bias current pointing to bias-independent resistivity fluctuations as a source of the observed noise. The normalized power spectral density appears inversely proportional to the number of carriers in the probed sample volume, in agreement with the phenomenological Hooge law. For the proton-implanted ZnO microwire and at 1 Hz we obtain a normalized power spectral density as low as [Formula: see text] Hz(-1).

HIV-1 Aspartic Proteinase: High-Level Production and Automated Fluorometric Screening Assay of Inhibitors

The 99-amino-acid HIV-1 aspartic proteinase was expressed to high levels in Escherichia coli using a T7 expression system. About 50% of the insoluble material after sonication of the bacteria was composed of aggregated proteinase. Subsequent renaturation and purification yielded large quantities of a homogeneous enzyme able to cleave various heptapeptidic substrates in vitro with a Km around 2.5 mM. A fluorometric assay has been devised to allow automated screening of HIV proteinase inhibitors based on an analogous renin assay. We used the synthetic intramolecularly quenched fluorogenic substrate Suc-TLNFPIS-4MCA based on the heptapeptide TLNFPIS, which encompasses the proteinase/reverse transcriptase junction, coupled to the fluorophore 7-amino-4-methylcoumarin and blocked at the amino-terminus by a succinyl group. The enzyme cleaves the substrate between phenylalanine and proline, and conditions were optimized for liberation of 7AMC from the generated PIS-4MCA with aminopeptidase M as secondary enzyme. 7AMC was monitored with a microplate fluorescence scanner. The known aspartic proteinase inhibitor pepstatin A consistently gave Ki = 2 × 10−6M. Other synthetic and natural compounds are currently being tested.

Proteomic analysis of the TerC interactome: Novel links to tellurite resistance and pathogenicity

The tellurite resistance gene operon (ter) is widely spread among bacterial species, particularly pathogenic species. The ter operon has been implicated in tellurite resistance, phage inhibition, colicine resistance, and pathogenicity. The TerC protein represents one of the key proteins in tellurite resistance and shows no significant homology to any protein of known function. So far, there is no experimental evidence for TerC interaction partners. In this study, proteomic-based methods, including blue native electrophoresis and co-immunoprecipitation combined with LC-MS/MS, have been used to identify TerC interaction partners and thus providing indirect evidence for tentative functions of TerC in Escherichia coli. An interactome has been constructed and robust physical interaction of integral membrane protein TerC with TerB, DctA, PspA, HslU, and RplK has been shown. The TerC-TerB complex appears to act as a central unit that may link different functional modules with biochemical activities of C4-dicarboxylate transport, inner membrane stress response (phage shock protein regulatory complex), ATPase/chaperone activity, and proteosynthesis. In previous reports, it was hypothesized that a transmembrane unit formed by TerC protein may interact with the TerD family, but herein neither TerD nor TerE proteins were identified as TerC complex components. We propose that TerD/TerE participates in tellurite resistance through TerC-independent action.

2-amino-N-(2,6-dichloropyridin-3-yl)acetamide derivatives as a novel class of HBV capsid assembly inhibitor

Capsid structure is crucial for the maturation and maintenance of the stable hepatitis B virion. Therefore, chemicals that inhibit capsid assembly might potentially act as potent antiviral compounds. However, only a few chemicals are known to block the capsid assembly process and further viral proliferation. In this study, we present a novel family of capsid assembly inhibitors that act against hepatitis B virus (HBV). Based on X-ray crystallographic data of the HBV core protein (Cp), we built dimer and hexamer structural models to be used in library searches. Several chemicals in the 2-amino-N-(2,6-dichloropyridin-3-yl)acetamide family were predicted to have high affinity for the groove structure in Cp. Using in vitro assembly and the HepG2.2.15 cell culture test, we verified that these chemicals demonstrated inhibitory effects on capsid assembly. Furthermore, we investigated the combinatorial effects of these assembly inhibitor chemicals with lamivudine and revealed that, in combination, they have synergistic inhibitory effects on decreasing viral concentration. We propose that these inhibitors could be utilized as an effective combination treatment against HBV infection.

Notch1 increases Snail expression under high reactive oxygen species conditions in hepatocellular carcinoma cells

Notch1 and reactive oxygen species (ROS) modulate important pathways associated with tumor development and progression. Notably, Notch1 expression is upregulated in 41.8% of hepatocellular carcinoma (HCC) patients and ROS levels increases as HCC progresses from Grade I to Grade III. It has been established that Notch1 and ROS modulate Snail expression in malignant tumors; however, the mechanism regulating Snail protein expression is not yet known. In this study, we observed that Notch1 and ROS cooperatively increase the levels of Snail protein in Huh7 (hepatoma) cells. On its own, signaling through Notch1 increases transcription of Snail without changing protein levels. In contrast, the combined activation of the Notch1 and ROS-induced phosphoinositide 3-kinase/Akt (PI3K/Akt) signaling pathways resulted in the high expression of Snail protein. This increase in Snail expression was associated with increased Huh7 cells invasiveness. Furthermore, we observed that correlation between Snail and Notch1 expression was the strongest in advanced grade HCC tissue. In conclusion, Notch1 and ROS-induced PI3K/Akt signals cooperatively increase Snail expression and may induce malignancy in HCC.

Single-molecule microscopy of the green fluorescent protein using simultaneous two-color excitation

In vivo microscopy of the Green Fluorescent Protein (GFP), the most important label in cell biology, with single-molecule sensitivity is hampered by an insufficient signal-to-noise ratio. A significant improvement is obtained with a novel two-color excitation technique. The picture clearly shows the increased brightness of GFP in in vitro single-molecule assays and in live-cell microscopy under two-color illumination (upper cell) as compared to normal illumination (lower cell).

Magnetic dynamic properties of electron-doped La(0.23)Ca(0.77)MnO3 nanoparticles

Magnetic properties of basically antiferromagnetic La(0.23)Ca(0.77)MnO(3) particles with average sizes of 12 and 60 nm have been investigated in a wide range of magnetic fields and temperature. Particular attention has been paid to magnetization dynamics through measurements of the temperature dependence of ac-susceptibility at various frequencies, the temperature and field dependence of thermoremanent and isothermoremanent magnetization originating from nanoparticles shells, and the time decay of the remanent magnetization. Experimental results and their analysis reveal the major role in magnetic behaviour of investigated antiferromagnetic nanoparticles played by the glassy component, associated mainly with the formation of the collective state formed by ferromagnetic clusters in frustrated coordination at the surfaces of interacting antiferromagnetic nanoparticles. Magnetic behaviour of nanoparticles has been ascribed to a core-shell scenario. Magnetic transitions have been found to play an important role in determining the dynamic properties of the phase separated state of coexisting different magnetic phases.

The temporal and spatial distribution of macrophage subpopulations during arteriogenesis

Chronic arterial occlusion leads to growth of collaterals - a process termed arteriogenesis, in which macrophages play a prominent role in remodelling and growth. However, a detailed analysis which of distinct macrophage subpopulations involved in arteriogenesis has never been performed. In the present study the temporal and spatial distribution of macrophage subtypes during arteriogenesis in a rat model with chronically elevated fluid shear stress (FSS) is investigated. Local macrophage subpopulations were histologically immuno-phenotyped using CD68 (a ubiquitous macrophage marker) and CD163, a specific M2 macrophage marker. Without occlusion few M2-macrophages reside in the perivascular space. Early after occlusion (12h) the number of M2 macrophages increases strongly and M1 macrophages begin emerging into the collateral. After 3 days they appear in the perivascular space. Both macrophage subtypes increase until 28d after treatment, whereas M2 macrophages dominate at the site of collateral growth. The local distribution of the subpopulations changes during the arteriogenic process. Whereas M1 macrophages are detected directly adjacent to the media, M2 macrophages are present in the most outer perivascular region of the growing collateral vessel. Systemic alterations of blood leucocytes in mice after femoral artery ligature (FAL) were investigated by FACS analysis of serial blood samples. During collateral remodelling histological changes were not reflected in circulating monocytes in the peripheral blood. The activation state of macrophages in mice with FAL was modulated by injections of either dexamethasone or the interleukins IL10 or IL3/IL14. The arteriogenic response was assessed by hind limb perfusion with laser Doppler measurements after 3, 7 and 14d. Suppressing inflammatory monocyte subtypes (M1) with dexamethasone led to impaired perfusion recovery after FAL in mice, whereas IL10 or IL4/IL13 application significantly increased perfusion recovery. This investigation demonstrates that a forced shift towards M2 macrophages improves the arteriogenic response. The distinct early increase and spatial distribution of M2 macrophages support the idea that this subtype plays a predominant role during collateral remodelling.

Adjuvant tamoxifen in breast-cancer-treatment in postmenopausal women - occurrence of thromboembolic complications

Of 441 postmenopausal breast cancer patients who received adjuvant tamoxifen, 19 had thromboembolic accidents (4.3%). All were in remission when thrombosis occurred. One patient died of bilateral pulmonary embolism. In the other cases, thromboembolic disorders were found to be reversible after the withdrawal of tamoxifen and anticoagulant treatment. Some patients had a history of vascular disorders, and others required prolonged bed rest which may have contributed as an aggravating circumstance to thrombotic events. Our study suggests that thromboembolic risk factors as well as potential vascular disorders induced by aggravating conditions have to be carefully examined in postmenopausal patients treated by adjuvant tamoxifen therapy. This is especially true in women with lobular breast cancer and aged more than 60 years.

Magnetic behaviour of interacting antiferromagnetic nanoparticles

Magnetic properties of interacting La(0.2)Ca(0.8)MnO(3) nanoparticles have been investigated. The field-induced transition from antiferromagnetic (AFM) to ferromagnetic (FM) state in the La(0.2)Ca(0.8)MnO(3) bulk has been observed at exceptionally high magnetic fields. For large particles, the field-induced transition widens while magnetization progressively decreases. In small particles the transition is almost fully suppressed. The thermoremanence and isothermoremanence curves constitute fingerprints of irreversible magnetization originating from nanoparticle shells. We have ascribed the magnetic behaviour of nanoparticles to a core-shell scenario with two main magnetic contributions; one attributed to the formation of a collective state formed by FM clusters in frustrated coordination at the surfaces of interacting AFM nanoparticles and the other associated with inner core behaviour as a two-dimensional diluted antiferromagnet.

Generation, selection and preclinical characterization of an Fc-optimized FLT3 antibody for the treatment of myeloid leukemia

The therapeutic efficacy of humanized or chimeric second-generation antitumor antibodies is clearly established, but often limited. In recent years, defined modifications of the glycosylation pattern or the amino-acid sequence of the human immunoglobulin G1 Fc part have resulted in the development of third-generation antibodies with improved capability to recruit Fc receptor-bearing effector cells. The first antibodies of this kind, currently evaluated in early clinical trials, are directed against lymphoma-associated antigens. Fc-engineered antibodies targeting myeloid leukemia are not yet available. We here report on the generation and preclinical characterization of an Fc-optimized antibody directed to the FMS-related tyrosine kinase 3 (FLT3), an antigen expressed on the leukemic blasts of all investigated patients with acute myeloid leukemia (AML). This antibody, termed 4G8SDIEM, mediated markedly enhanced cellular cytotoxicity against FLT3-expressing cell lines as well as blasts of AML patients. FLT3 expression levels on AML cells varied between 300 and 4600 molecules/cell and, in most cases, were substantially higher than those detected on normal hematopoietic precursor cells and dendritic cells (approximately 300 molecules/cell). Antibody-mediated cytotoxicity against these normal cells was not detectable. 4G8SDIEM has been produced in pharmaceutical quality in a university-owned production unit and is currently used for the treatment of leukemia patients.

Humanized theta-defensins (retrocyclins) enhance macrophage performance and protect mice from experimental anthrax infections

Retrocyclins are humanized versions of the -defensin peptides expressed by the leukocytes of several nonhuman primates. Previous studies, performed in serum-free media, determined that retrocyclins 1 (RC1) and RC2 could prevent successful germination of Bacillus anthracis spores, kill vegetative B. anthracis cells, and inactivate anthrax lethal factor. We now report that retrocyclins are extensively bound by components of native mouse, human, and fetal calf sera, that heat-inactivated sera show greatly enhanced retrocyclin binding, and that native and (especially) heat-inactivated sera greatly reduce the direct activities of retrocyclins against spores and vegetative cells of B. anthracis. Nevertheless, we also found that retrocyclins protected mice challenged in vivo by subcutaneous, intraperitoneal, or intranasal instillation of B. anthracis spores. Retrocyclin 1 bound extensively to B. anthracis spores and enhanced their phagocytosis and killing by murine RAW264.7 cells. Based on the assumption that spore-bound RC1 enters phagosomes by "piggyback phagocytosis," model calculations showed that the intraphagosomal concentration of RC1 would greatly exceed its extracellular concentration. Murine alveolar macrophages took up fluorescently labeled retrocyclin, suggesting that macrophages may also acquire extracellular RC1 directly. Overall, these data demonstrate that retrocyclins are effective in vivo against experimental murine anthrax infections and suggest that enhanced macrophage function contributes to this property.

Survival of bacteria and fungi in relation to water activity and the solvent properties of water in biopolymer gels

Survival of bacteria (Rhizobium, Agrobacterium, and Arthrobacter spp.), fungal spores (Penicillium sp.), and yeasts (Saccharomyces sp.) was studied in relation to water activity (a(w)) and the presence of nutritive solutes. The cells were entrapped in polysaccharide gels, as is done to immobilize cells or enzymes, and then dehydrated. The number of living cells (10 g of dry polymer) remained constant for periods of storage of >3 years at 28 degrees C when the inocula were kept at an a(w) of <0.069. At a(w) values between 0.069 and 0.83 the number of survivors diminished more and more rapidly as the a(w) was raised. For a given a(w) and organism, there were large differences in survival rate as a function of the nutritive solutes used to culture the microorganisms. Low-molecular-weight compounds (with three or five carbon atoms) had a deleterious effect on survival, whereas compounds of higher molecular weight (C(6) to C(12)) had a protecting effect. Thus, the a(w) alone was not a sufficient explanation for the deterioration of the inocula. Survival seemed to be more directly related to some properties of the water in the biopolymer. New concepts such as the discontinuity of properties of water and the point of mobilization of solutes, already proposed by Duckworth and Kelly (J. Food Technol. 8:105-113, 1973) and Seow (J. Sci. Food Agric., 26:535-536, 1975), have been taken into consideration to explain the interactions of water with the biopolymer and their specific effects on the microorganisms.

Collective effects in charge transfer within a hybrid organic-inorganic system

A collective electron transfer (ET) process was discovered by studying the current noise in a field effect transistor with light-sensitive gate formed by nanocrystals linked by organic molecules to its surface. Fluctuations in the ET through the organic linker are reflected in the fluctuations of the transistor conductivity. The current noise has an avalanche character. Critical exponents obtained from the noise power spectra, avalanche distributions, and the dependence of the average avalanche size on avalanche duration are consistent with each other. A plausible model is proposed for this phenomenon.

Assessment of quality of life using FACT-G survey in a phase I trial in cancer patients

e20709

Background: Quality of life (QoL) assessment in clinical trials has been gaining more attention. FACT-G surveys have been validated to assess QoL in clinical trials involving oncology patient (Cella DF et al, J Clin Oncol 11:570–579, 1993). However, there is paucity of evaluation of QoL in patients with advanced cancer participating in Phase I clinical trials. Methods: FACT-G surveys were conducted within the context of a Phase I trial to identify a safe dose and potential drug-drug interations of capecitabine and irinotecan combination (Goel, S et al, Invest New Drugs 25:237–245, 2007). The FACT-G survey consists of 28 questions in 5 sections, namely, physical well-being, social/family well-being, emotional well-being, relationship with doctor, and functional well-being). Patients were requested to complete the FACT-G surveys at baseline and every two cycles thereafter (each cycle of 3 weeks duration). Results: Forty-one of 47 patients with advanced solid tumors who participated in the clinical trial completed FACT-G surveys. Mean scores were calculated for each time point. The mean QoL scores at baseline and post cycle 2 were 53 and 58, respectively (p = 0.1). Post cycle 4, the mean QoL score was 62 [p = 0.01, (vs. baseline)]. Following cycle 4, the number of respondents decreased to the extent where we were unable to ascertain any further changes in the QoL scores. Conclusions: It is feasible to use FACT-G survey as a tool to assess QoL in patients participating in an oncology phase I clinical trial. Although the sample size of the patient population was not powered for any statistical significance, there was a trend toward improving QoL based on FACT-G survey scores. This suggests that phase I clinical trials may provide improvement of QoL for some patients. FACT-G is a useful tool in assessing QoL in oncology phase I trial study population.

No significant financial relationships to disclose.

Protein biomarker analysis by mass spectrometry in patients with rheumatoid arthritis receiving anti-tumor necrosis factor-alpha antibody therapy

OBJECTIVE

To investigate the mechanism of action of anti-tumor necrosis factor-alpha (TNF-alpha) antibody in patients with rheumatoid arthritis (RA), we analyzed serum or plasma proteins by mass spectrometry system.

METHODS

Ten RA patients who received treatment with anti-TNF-alpha antibody were studied. Samples obtained before and after therapy were analyzed by a two-dimensional liquid chromatography tandem mass spectrometry (2D LC-MS/MS) system after pretreatment by a recently developed method to remove high molecular weight proteins.

RESULTS

Using this system, certain proteins were identified after treatment with anti-TNF-alpha antibody, including proteins related to the TNF-alpha-mediated pathway for nuclear factor kappa B (NF-kappaB) activation and/or to the metabolism (including regeneration) of articular cartilage.

CONCLUSION

Our mass spectrometry system appears to be useful for proteomic analysis. The efficacy of anti-TNF-alpha antibody therapy for RA may be related to various consequence of the inhibition of TNF-alpha activity.

The first linkage map of the plant-pathogenic basidiomyceteTyphula ishikariensis

Speckled snow mold, caused by the basidiomycete Typhula ishikariensis Imai, is one of the most prominent winter diseases on perennial grasses and cereal crops in the northern hemisphere. The first linkage map of T. ishikariensis was constructed using a population of 93 sibling monokaryons derived from a single dikaryotic hybrid isolate that was created by a hyphal fusion of two monokaryotic parental isolates. The parental isolates were produced from a pathogenic dikaryotic isolate collected from a golf course in Wisconsin. The two parents exhibit significant differences in the production of aerial mycelium and sclerotia, and in their aggressiveness on creeping bentgrass ( Agrostis stolonifera L.). A total of 251 loci were mapped, comprising 89 inter-simple sequence repeat (ISSR) and 160 random amplified polymorphic DNA (RAPD) markers along with 2 phenotype-based mating-type (MAT) loci. The MAT loci were mapped on linkage groups (LGs) 1 and 7. The markers were evenly distributed over 7 LGs, covering 436 cM with an average marker interval of 2.2 cM. Seven chromosomes were cytologically observed using germ tube bursting methods with acetocarmine staining. This reference linkage map of T. ishikariensis should provide a framework for the mapping of quantitatively controlled traits such as fungal growth, survival, and virulence/avirulence under low temperatures. The map should also be utilized for studying the genome organization of the cold-loving plant-pathogenic Typhula spp. and for comparative genome analysis among fungal taxa.

Reassessment of vegetative compatibility of Sclerotinia homoeocarpa using nitrate-nonutilizing mutants

Nitrate-nonutilizing (nit) mutants were recovered for the first time from 21 isolates of Sclerotinia homoeocarpa collected in the United States. Mutants were selected from shredded mycelium of each isolate when cultured on water agar medium amended with 4% (wt/vol) potassium chlorate. The mutants could be classified into three phenotypes: nit1, nit3, and NitM, based on their growth on minimal medium (Czapek solution agar) supplemented with NaNO(2) or hypoxanthine. Complementary heterokaryons were observed in pairings between different phenotypes of nit mutants derived from compatible isolates, but not in self-fusions or pairings between incompatible isolates. The vigor of prototrophic growth varied with isolates and mutant phenotypes. Strong and continuous heterokaryons, as well as weak and spontaneous ones, formed depending on pairings of nit mutants. Stable heterokaryons between compatible isolates, but apoptotic reactions between incompatible isolates, were observed immediately after hyphal fusion under the epifluorescence microscope. The 21 isolates used in this study, which were previously assigned into 11 different vegetative compatibility groups (VCGs) based on the formation of a barrage zone at the contact site of paired isolates on complete medium (potato dextrose agar), were regrouped into five VCGs based on heterokaryon formation between nit mutants on minimal medium.

Functionalized polymer colloids bearing primary amino groups

Polymer colloids are prepared via radicalic emulsion polymerisation of butylacrylate. Functionalization with amino groups is achieved by copolymerisation of 2-amino-ethylmethacrylates. In order to over-compensate the positive surface charges resulting from the amino groups additionally vinylbenzenesulfonic acid is copolymerized. The size of the resulting particles is controlled by the molar ratio of amino to sulfonic acid groups. The suitability of amino groups for coupling reactions is demonstrated by electrophilic addition of fluorescein-5-isothiocyanate. The resulting particles are characterized by dynamic light scattering and zeta potential measurements as well as by optical spectroscopy. The suitability of labelled particles for optical tracer experiments is demonstrated by fluorescence correlation spectroscopy.

Mapping and Comparative Analysis of QTL for Crown Rust Resistance in an Italian x Perennial Ryegrass Population

ABSTRACT Crown rust (Puccinia coronata f. sp. lolli) is a serious fungal foliar disease of perennial ryegrass (Lolium perenne L.) and Italian ryegrass (L. multiflorum Lam.), which are important forage and turf species. A number of quantitative trait loci (QTL) for crown rust resistance previously were identified in perennial ryegrass under growth chamber or greenhouse conditions. In this study, we conducted a QTL mapping for crown rust resistance in a three-generation Italian x perennial ryegrass interspecific population under natural field conditions at two locations over 2 years. Through a comparative mapping analysis, we also investigated the syntenic relationships of previously known crown rust resistance genes in other ryegrass germplasms and oat, and genetic linkage between crown rust resistance QTL and three lignin genes: LpOMT1, LpCAD2, and LpCCR1. The interspecific mapping population of 156 progeny was developed from a cross between two Italian x perennial ryegrass hybrids, MFA and MFB. Because highly susceptible reactions to crown rust were observed from all perennial ryegrass clones, including two grandparental clones and eight clones from different pedigrees tested in this study, two grandparent clones from Italian ryegrass cv. Floregon appeared to be a source of the resistance. Two QTL on linkage groups (LGs) 2 and 7 in the resistant parent MFA map were detected consistently regardless of year and location. The others, specific to year and location, were located on LGs 3 and 6 in the susceptible parent MFB map. The QTL on LG2 was likely to correspond to those previously reported in three unrelated perennial ryegrass mapping populations; however, the other QTL on LGs 3, 6, and 7 were not. The QTL on LG7 was closely located in the syntenic genomic region where genes Pca cluster, Pcq2, Pc38, and Prq1b resistant to crown rust (P. coronata f. sp. avenae) in oat (Avena sativa L.) were previously identified. Similarly, the QTL on LG3 was found in a syntenic region with oat genes resistant to crown rust isolates PC54 and PC59. This indicates that the ortholoci for resistance genes to different formae speciales of crown rust might be present between two distantly related grass species, ryegrass and oat. In addition, we mapped four restriction fragment length polymorphism loci for three key ryegrass lignin genes encoding caffeic acid-O-methyltransferase, cinnamyl alcohol dehydrogenase, and cinnamoyl CoA-reductase on LG7. These loci were within a range of 8 to 17 centimorgans from the QTL on LG7, suggesting no tight linkage between them. The putative ortholoci for those lignin biosynthesis genes were identified on segments of rice (Oryza sativa L.) chromosomes 6 and 8, which are the counterparts of ryegrass LG7. Results from the current study facilitate understanding of crown rust resistance and its relationship with lignin biosynthesis, and also will benefit ryegrass breeders for improving crown rust resistance through marker-assisted selection.

Variation in Bentgrass Susceptibility to Typhula incarnata and in Isolate Aggressiveness Under Controlled Environment Conditions

Typhula incarnata, the causal agent of gray snow mold, is an important winter pathogen of turfgrasses in the northern United States. The relative susceptibility of cultivars of three bent-grass species (creeping, colonial, and velvet bentgrass) to Typhula incarnata and the aggressiveness of 15 T. incarnata isolates obtained from infected turfgrasses on golf courses in Michigan, Minnesota, and Wisconsin were evaluated under controlled conditions. A hypersensitive type of resistance response to T. incarnata was not observed in any cultivar. Disease severity increased with higher inoculum concentration of T. incarnata. Colonization by gray snow mold gradually decreased with increasing plant age from 11 weeks after seeding in most cultivars tested, suggesting that age-related resistance was expressed over time. There were significant differences in disease severity among the three bentgrass species, particularly between tetraploid (creeping and colonial) and diploid (velvet) species, and among cultivars within each species, indicating varying levels of susceptibility to T. incarnata. All 15 isolates were pathogenic on bentgrass and were significantly different in aggressiveness, but aggressiveness was not related to geographic origin. Therefore, turfgrass breeders should be able to use one or a few virulent representative isolates of the pathogen to screen for resistance.

Mapping QTL for dollar spot resistance in creeping bentgrass (Agrostis stolonifera L.)

Dollar spot caused by Sclerotinia homoeocarpa F. T. Bennett is the most economically important turf disease on golf courses in North America. Dollar spot resistance in a creeping bentgrass cultivar would greatly reduce the frequency, costs, and environmental impacts of fungicide application. Little work has been done to understand the genetics of resistance to dollar spot in creeping bentgrass. Therefore, QTL analysis was used to determine the location, number and effects of genomic regions associated with dollar spot resistance in the field. To meet this objective, field inoculations using a single isolate were performed over 2 years and multiple locations using progeny of a full sib mapping population '549 x 372'. Dollar spot resistance seems to be inherited quantitatively and broad sense heritability for resistance was estimated to be 0.88. We have detected one QTL with large effect on linkage group 7.1 with LOD values ranging from 3.4 to 8.6 and explaining 14-36% of the phenotypic variance. Several smaller effect QTL specific to rating dates, locations and years were also detected. The association of the tightly linked markers with the LG 7.1 QTL based on 106 progeny was further examined by single marker analysis on all 697 progeny. The high significance of the QTL on LG 7.1 at a sample size of 697 (P < 0.0001), along with its consistency across locations, years and ratings dates, indicated that it was stable over environments. Markers tightly linked to the QTL can be utilized for marker-assisted selection in future bentgrass breeding programs.

[Interactive thresholded volumetry of abdominal fat using breath-hold t1-weighted magnetic resonance imaging]

PURPOSE

Development of a feasible and reliable method for determining abdominal fat using breath-hold T1-weighted magnetic resonance imaging.

MATERIALS AND METHODS

The high image contrast of T1-weighted gradient echo MR sequences makes it possible to differentiate between abdominal fat and non-fat tissue. To obtain a high signal-to-noise ratio, the measurements are usually performed using phased array surface coils. Inhomogeneity of the coil sensitivity leads to inhomogeneity of the image intensities. Therefore, to examine the volume of abdominal fat, an automatic algorithm for intensity correction must be implemented. The analysis of the image histogram results in a threshold to separate fat from other tissue. Automatic segmentation using this threshold results directly in the fat volumes. The separation of intraabdominal and subcutaneous fat is performed by interactive selection in a last step.

RESULTS

The described correction of inhomogeneity allows for the segmentation of the images using a global threshold. The use of semiautomatic interactive volumetry makes the analysis more subjective. The variance of volumetry between observers was 4.6 %. The mean time for image analysis of a T1-weighted investigation lasted less than 6 minutes.

CONCLUSION

The described method facilitates reliable determination of abdominal fat within a reasonable period of time. Using breath-hold MR sequences, the time of examination is less than 5 minutes per patient.