Nocturnal blood glucose and IGFBP-1 changes in type 1 diabetes: Differences in the dawn phenomenon between insulin regimens

OBJECTIVE

Insulin-like growth factor binding protein-1 (IGFBP-1) is known to regulate the bioavailability of insulin-like growth factor (IGF) and the levels of IGFBP-1 are increased in the morning in patients with type 1 diabetes mellitus. We investigated the nocturnal fluctuations of glucose, IGFBP-1, and free IGF-1 levels with three insulin regimens.

RESEARCH DESIGN AND METHODS

Forty-eight type 1 diabetes patients were divided into three groups according to their basal insulin therapy (continuous subcutaneous insulin infusion [CSII], insulin glargine, NPH insulin). Blood samples were obtained every 2 h between 2 300 h and 0700 h to measure plasma glucose, IGFBP-1 and free IGF-1 levels.

RESULTS

The dawn phenomenon was more frequent with NPH (62.1%) than with glargine (16.6%, p<0.05) and CSII (14.3%, p<0.05). In the NPH group, the serum IGFBP-1 levels were markedly increased from 21.0+/-3.6 ng/ml at 2 300 h to 200.3+/-21.8 ng/ml at 0700 h and free IGF-1 levels were inversely decreased; these changes were partially suppressed in the CSII and glargine groups.

CONCLUSIONS

The use of insulin regimens that provide sufficient insulin levels in the early morning can suppress the dawn phenomenon, leading to improved glycemic control. The increase in circulating IGFBP-1 in the morning, as a result of waning of insulin action, lowers free IGF-1 levels and may cause insulin resistance.

Delivery of NKG2D Ligand Using an Anti-HER2 Antibody-NKG2D Ligand Fusion Protein Results in an Enhanced Innate and Adaptive Anti-Tumor Response

Background: NKG2D ligands activate via the NKG2D receptor expressed on effector cells belonging to both the innate (NK) and adaptive immune systems (CD8+ T cells). Over-expression of NKG2D ligand on the surface of tumor cells leads to tumor regression in several murine models. We reasoned that antibody targeting of NKG2D ligand to tumor cells could also be used to evoke an enhanced anti-tumor immune response.Methods: We fused the murine NKG2D ligand, Rae-1β, to the 3' end of an anti-HER2 IgG3 containing an intact Fc domain (anti-HER2 IgG3-Rae-1β) to target NKG2D ligand to HER2+ breast tumor cells. The cytotoxicity of the fusion proteins was tested in vitro in direct and indirect assays with the murine NK cell line, KY-2. Anti-tumor efficacy was examined in a murine mammary tumor model.Results: Anti-HER2 IgG3-Rae-1β fusion protein bound to both the HER2 antigen, and to NKG2D as determined by flow cytometry. Anti-HER2 IgG3-Rae-1β fusion induced enhanced cytotoxicity of NK effectors against HER2 expressing tumor cells in vitro. EMT6-HER2 bearing BALB/c mice treated with anti-HER2 IgG3-Rae-1β showed markedly decreased tumor growth relative to anti-HER2 IgG3 or PBS injected control mice. Treatment of mice that were implanted on one flank with EMT6 and contralaterally implanted with EMT6-HER2, resulted in prompt regression of EMT6-HER2, and delayed regression of EMT6, suggesting “epitope spreading.” To examine the involvement of NK, CD4, or CD8 cells in the growth inhibition of the Rae-1β fusion protein targeted tumors, we performed lymphocyte subset depletion studies. Mice depleted of either NK cells or CD8+ T cells showed decreased inhibition of tumor growth following treatment with anti-HER2 IgG3-Rae-1β, compared to control mice. These results suggest that NK cells and CD8+ cells play an important role in the anti-tumor activity of anti-HER2 antibody-Rae-1β fusion. Anti-HER2 IgG3-Rae-1β also inhibited growth of EMT6-HER2 in FcγR-/- mice, indicating activity of the fusion in the absence of FcR interaction. No anti-tumor efficacy of anti-HER2 IgG3-Rae-1β was observed in IFNγ-/- mice.To determine if anti-HER2 antibody-Rae-1β fusion led to priming of an adaptive response, twelve mice that had previously rejected EMT6-HER2 tumors following treatment with anti-HER2 IgG3-Rae-1γ, were rechallenged with either EMT6-HER2, or with parental EMT6. Five of six mice rechallenged with EMT6-HER2 and five of six mice rechallenged with EMT6 showed no evidence of tumor growth at day 25, while both EMT6 and EMT6-HER2 grew rapidly in six of six control mice, respectively.Conclusion: Antibody-NKG2D ligand fusion proteins administration leads to an enhanced anti-tumor innate and adaptive immune response. The immune response evoked by targeting of the fusion to HER2, a single surface antigen, encompassed additional non-targeted antigens. Antibody-NKG2D ligand fusion proteins could potentially be used to treat other malignancies by substituting alternate tumor specificities. Murine NKG2D ligand in the antibody fusion molecules could be replaced with human NKG2D ligands for testing in man.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6102.

Prognostic Significance of Nodal and PgR Status on Early Relapse in Operable HER-2 Positive Breast Cancer from the Pre-Trastuzumab Era

Background: Over the last decade, trastuzumab has become a standard adjuvant treatment option in HER-2 positive breast cancers. However, with a mainly 'on-treatment' effect only, the economic burden and adverse effects incurred from its routine use for 1 year following completion of chemotherapy, there emerges a need to identify a group of HER-2 positive breast cancers at low-risk for relapse. We, therefore, investigated potential prognostic factors in a cohort of HER-2 positive breast cancers in the era before trastuzumab, especially focusing on hormonal status.Methods: We retrospectively reviewed the data of 240 trastuzumab-naïve patients with a HER-2 FISH-positive breast cancer who had primary surgery at University Hospitals Leuven between January 2000 and December 2005. We collected data including age at diagnosis, menopausal status, histologic type, tumor size, grade, lymph node involvement, estrogen receptor (ER) /progesterone receptor (PgR) status, and disease-free survival (DFS) outcome. A multivariate Cox hazard model was used to identify prognostic factors and the cumulative DFS rate was determined using the Kaplan-Meier method.Results: After a median follow-up of 57.5 months there were 50 breast cancer related events meaning that 5-year DFS rate was 78.4% for the entire cohort. Median time to first event was 20 months and ranged from 4 to 96 months. Cox model revealed that only PgR status and lymph node involvement were independent prognostic factors for disease relapse. (p = 0.03 and p &lt; 0.01 respectively). In Kaplan-Meier analysis, patients with PgR+ showed better DFS rate than those with PgR- (figure 1; 83.8% vs. 73.1%, p = 0.02) while ER status didn't reach statistical significance (p = 0.154).Nodal involvement ≥4 was strongly associated with poor DFS rate compared with node negativity. (p = 0.00). Of note, a subgroup of patients with PgR+ and LN-. presented no relapse within the first two years after surgery (figure 2).Conclusions: In this series of HER-2 positive breast cancers, PgR and nodal status were strong prognostic factors for early breast cancer relapse. Patients with a PgR+/LN- phenotype were unlikely to relapse within the first two years of surgery. We propose to evaluate the added benefit of adjuvant trastuzumab to chemotherapy in women with this phenotype as such data are yet not available from the major adjuvant trastuzumab trials.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6046.

Effects of glucokinase activators GKA50 and LY2121260 on proliferation and apoptosis in pancreatic INS-1 beta cells

AIMS/HYPOTHESIS

Glucokinase (GK), an enzyme that phosphorylates glucose to form glucose 6-phosphate, serves as the glucose sensor that regulates insulin secretion in beta cells. GK activators (GKAs) activate GK via binding to an allosteric site of the enzyme. GKAs increase glucose-stimulated insulin secretion and decrease blood glucose levels. Using the differentiated beta cell line INS-1, we investigated the role of GKAs in promoting beta cell growth and survival and preventing beta cell apoptosis induced by chronic exposure to high levels of glucose.

METHODS

Proliferation was assessed using BrdU incorporation. Apoptosis was measured using caspase-3 activity. Immunoblot analysis was used to detect protein levels and the degree of phosphorylation.

RESULTS

The GK agonists GKA50 and LY2121260 increased both cell replication and cell numbers when tested at basal levels of glucose (3 mmol/l) in INS-1 cells. GKAs promoted INS-1 cell proliferation via upregulation of insulin receptor substrate-2 and subsequent activation of protein kinase B phosphorylation. GKA50 also prevented the INS-1 cell apoptosis that was induced by chronic high glucose conditions, probably via an increase in GK protein levels and normalisation of the apoptotic protein BCL2-associated agonist of cell death (BAD) and its phosphorylation. As a result of the reduction in cell apoptosis, GKA50 prevented cell loss and maintained glucose-stimulated insulin secretion. In addition, the anti-apoptotic activity of GKA50 was significantly abrogated by other GKAs that do not inhibit apoptosis, suggesting that direct binding of GKA50 to GK is essential for its anti-apoptotic effect.

CONCLUSION/INTERPRETATION

Our results suggest novel roles of GKAs in promoting beta cell growth and preventing chronic-hyperglycaemia-induced beta cell apoptosis. Thus, GKAs may provide novel therapeutics that increase beta cell mass to maintain euglycaemia in diabetes.

Complexation of Cm(III)/Eu(III) with silicates in basic solutions

The complexation of Cm(III) and Eu(III) with dissolved silica was studied by solubility measurement and time resolved laser fluorescence spectroscopy (TRLFS) in basic solutions over a range of total silica concentrations and ionic strengths (NaNO3). In initial experiments on the solubility of Eu(OH)3 in silicate containing solutions we observed a rapid increase in the soluble Eu(III) concentration under basic conditions. The Eu(III)/Cm(III) silicate complexes that formed caused a significant increase of the hypersensitive 5 D 0 → 2 F 2 band around 615 nm relative to the non-hypersensitive 5 D 0 → 7 F 1 band at 592 nm for Eu(III). Further studies of Eu(III) and Cm(III) containing solutions showed a shift of the fluorescence spectral maximum from 594 nm to up to 607 nm for Cm(III) along with a significant increase of fluorescence intensities. The fluorescence lifetimes for Eu(III) species increased from 115 μs to 1.8 ms in 3.0 M and 5.0 M NaNO3, corresponding to full coordination, and from 68 μs to 202 μs for Cm(III) in 0.1 M NaNO3, consistent with the removal of 6–7 water molecules upon silicate complexation. The variations of the fluorescence intensity and the concentrations of the monomeric and polymeric silicates suggested that in basic silicate solutions, Eu(III)/Cm(III) mainly complexes with polysilicates.

Visualization of inhomogeneous local magnetic field gradient due to susceptibility contrast

We visualized inhomogeneous local magnetic field (internal magnetic field) gradients arising from susceptibility contrast between an array of cylindrical glass tubes (solid matrix) and surrounding water (pore fluids) in a uniform applied magnetic field. MRI was performed to determine the spatially resolved decay rates due to diffusion in the internal magnetic field which were proportional to the strength of local gradient. We also spatially resolved the interference pattern of the cross-terms between the internal and the applied field gradient in order to extract the orientation of the internal field gradient. These experimental results were found to be consistent with the theoretical calculations. This work demonstrates a simple yet representative case for visualizing the strength and orientation of the local susceptibility induced magnetic field gradients in porous media.

High-resolution MRI of internal field diffusion-weighting in trabecular bone

Trabecular bone structure is known to play a crucial role in the overall strength, and thus fracture risk, of such areas of the skeleton as the vertebrae, spine, femur, tibiae, or radius. Several MR methods devoted to probing this structure depend upon the susceptibility difference between the solid bone matrix and the intervening fluid/marrow/fat, usually in the context of a linewidth (1/T(2)') measurement or mapping technique. A recently demonstrated new approach to this system involves using internal gradients to encode diffusion weighting, and extracting structural information (e.g., surface-to-volume ratio) from the resulting signal decay. This contrast method has been demonstrated in bulk measurements on cleaned, water-saturated bovine trabecular bone samples. In the present work, microscopic imaging (0.156 mm in-plane resolution) is performed in order to spatially resolve this contrast on the trabecular level, and confirm its interpretation for the bulk measurements. It is found that the local rate of decay due to diffusion in the internal field (DDIF) is maximal close to the trabecular surfaces. The overall decay rate in a lower resolution scan probes the abundance of these surfaces, and provides contrast beyond that found in conventional proton density weighted or T(1)-weighted imaging. Furthermore, a microscopic calculation of internal field distributions shows a qualitative distinction between the structural sensitivities of DDIF and T(2)'. DDIF contrast is highly localized around trabecular walls than is the internal field itself, making it a less sensitive but more specific measure of such important properties as trabecular number.

Modulation of firing activity by ATP in dopamine neurons of the rat substantia nigra pars compacta

ATP acts as a neurotransmitter or co-neurotransmitter in many areas of the CNS and peripheral nervous systems; however, little is known about the expression and functional role of purinoceptors (P2) in midbrain dopaminergic neurons. Therefore, we investigated P2X receptor expression and regulation of spontaneous firing activity in dopaminergic neurons of the substantia nigra pars compacta (SNc) in rats using patch-clamp and Ca(2+)-imaging techniques. In most neurons, application of ATP (1 microM-1 mM) increased firing rate dose-dependently (EC(50)=1.26+/-0.26 microM, n=45). When the P2-receptor agonists such as 2-methylthio-adenosine 5'-triphosphate (2-MeSATP) or ATPgammaS were applied or pressure-applied to the neuron, the firing activity increased together with a rise in cytosolic Ca(2+) concentration ([Ca(2+)]c), but application of beta,gamma-methylene ATP (P2X(1, 3) agonist) or methylthio-adenosine 5'-diphosphate (P2Y(1) agonist) had no effect. In many neurons, the effect of ATP was abolished by the application of the P2-receptor antagonists, suramin or pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid (PPADS). When ATP was applied in a Ca(2+)-free solution, there was no detectable change in [Ca(2+)]c, suggesting that ATP does not release Ca(2+) from intracellular stores. In the single-cell reverse transcription polymerase chain reaction (RT-PCR), we found that 65% of dopaminergic neurons expressed mRNAs for P2X receptors; positive amplifications of P2X(6) (57.1%), P2X(2/6) (25.0%), and P2X(4) mRNA (17.9%), respectively. From the above results, we could conclude that ATP modulates firing activities in the rat SNc dopaminergic neurons, possibly via P2X(2), P2X(2/6), and/or P2X(4) receptors.

Magnetic resonance in porous media: recent progress

Recent years have seen significant progress in the NMR study of porous media from natural and industrial sources and of cultural significance such as paintings. This paper provides a brief outline of the recent technical development of NMR in this area. These advances are relevant for broad NMR applications in material characterization.

NMR measurement of the magnetic field correlation function in porous media

The structure factor provides a fundamental characterization of porous and granular materials as it is the key for solid crystals via measurements of x-ray and neutron scattering. Here, we demonstrate that the structure factor of the granular and porous media can be approximated by the pair correlation function of the inhomogeneous internal magnetic field, which arises from the susceptibility difference between the pore filling liquid and the solid matrix. In-depth understanding of the internal field is likely to contribute to further development of techniques to study porous and granular media.

Peripheral nerve regeneration through the space formed by a chitosan gel sponge

The clinical treatment of traumatized peripheral nerves often requires grafting of autologous cutaneous nerves. However, there are drawbacks in sacrificing healthy nerves and tissue scarring. In this study, an artificial material, freeze-dried chitosan gel sponge, was examined as a scaffold for nerve regeneration in rats. An 8-mm gap was made by removing a segment of the sciatic nerve, and the distal and proximal stumps were sandwiched by chitosan gel sponge. Rats were killed at 4, 7, 14, and 28 days, and 2 and 4 months after the operation and histological and morphometric evaluations were performed. Regenerating axons were observed at 4 days after the operation. Regenerating nerves extended the distal stump at 14 days after surgery. By electron microscopy, numerous macrophages appeared to phagocyte chitosan, and made a dense cell layer on the chitosan. Regenerating axons did not touch the chitosan, and extended through the space surrounded by macrophage-stacked chitosan. Regenerating nerves were well-myelinated 2 months after surgery. Regenerating nerves were on average 2.45 and 2.75 microm in diameter at 2 and 4 months, respectively, after surgery. These results indicate that the chitosan gel sponge sandwich might be suitable as a graft for peripheral nerve regeneration.

Lung macrophages from bacille Calmette-Guérin-vaccinated guinea pigs suppress T cell proliferation but restrict intracellular growth of M. tuberculosis after recombinant guinea pig interferon-gamma activation

The guinea pig model of low-dose pulmonary tuberculosis has been used to study the pathogenesis of infection as well as the mechanisms of bacille Calmette-Guérin (BCG) vaccine-induced resistance. We investigated the function of lung cells from naive and BCG-vaccinated guinea pigs after enzymatic digestion of lung tissue with collagenase and DNase I. The total lung digest cells proliferated poorly to purified protein derivative (PPD) but comparatively better to ConA as assessed by [(3)H]-thymidine uptake. However, the non-adherent population obtained after plastic adherence of lung digests showed an enhanced response to concanavalin A (ConA) and PPD. Therefore, proliferation to ConA and PPD of nylon wool-purified T cells co-cultured with peritoneal (PMøs), alveolar (AMøs) or lung macrophages (LMøs) was assessed. Co-cultures of lung T cells and PMøs showed maximum proliferation to PPD, whereas proliferation was suppressed significantly by the addition of AMøs or LMøs. The response of T cells to ConA was unaffected in co-cultures. Incubation of co-cultures with recombinant guinea pig interferon-gamma (rgpIFN-gamma) did not reverse the suppression. In contrast, rgpIFN-gamma-treated plastic adherent LMøs that were non-specific esterase-positive were capable of reducing the intracellular growth of Mycobacterium tuberculosis. Similarly, total, non-adherent and adherent lung digest cells from BCG-vaccinated guinea pigs showed IFN-gamma and tumour necrosis factor (TNF)-alpha mRNA expression in response to ConA, lipopolysaccharide or PPD by reverse transcription-polymerase chain reaction followed by release of TNF protein but not IFN. These studies indicate that rgp-IFN-gamma-treated lung tissue macrophages from BCG-vaccinated guinea pigs are defective for inducing antigen-specific proliferation in T cells, but control the intracellular accumulation of virulent M. tuberculosis.

A single-scan method for measuring flow along an arbitrary direction

In this article, we demonstrate a single-scan method to measure an average flow velocity vector along an arbitrary direction. This method is based on the MMME sequence and utilizes static and pulsed magnetic field gradients along multiple directions for the optimal determination of flow velocity components in three-dimensional space. Experimentally measured average flow velocities from the flow induced phase shift with a single-scan MMME sequence show excellent agreements with the known flow rate, and the signal decay of each echo due to a velocity distribution is also quantitatively verified with known laminar flow patterns.

Rapid measurement of three-dimensional diffusion tensor

In this article, the authors demonstrate a rapid NMR method to measure a full three-dimensional diffusion tensor. This method is based on a multiple modulation multiple echo sequence and utilizes static and pulsed magnetic field gradients to measure diffusion along multiple directions simultaneously. The pulse sequence was optimized using a well-known linear inversion metric (condition number) and successfully tested on both isotropic (water) and anisotropic (asparagus) diffusion systems.

NAD+-linked 15-hydroxyprostaglandin dehydrogenase: structure and biological functions

NAD(+)-linked 15-hydroxyprostaglandin dehydrogenase (15-PGDH) catalyzes the oxidation of 15(S)-hydroxyl group of prostaglandins and lipoxins resulting in the formation of 15-keto metabolites which exhibit greatly reduced biological activities. Therefore, this enzyme has been considered the key enzyme responsible for the inactivation of prostaglandins and lipoxins. Both the cDNA and the genomic DNA of the 15-PGDH gene have been cloned. Structural characterization, transcriptional regulation and biological functions of this enzyme have been investigated. Molecular modeling corroborated with site-directed mutagenesis has identified key residues and domains involved in coenzyme and substrate binding. Catalytic mechanism has been proposed. Studies on the regulation of enzyme expression and activity by physiological and pharmacological agents have begun to uncover its significant roles in cancer, inflammation and reproduction. Apparently, 15-PGDH works with cyclooxygenase-2 to control the cellular levels of prostaglandins. Their reciprocal regulation within the same cells appears to determine the fate of the cells. Because of its ability to inactivate both prostaglandins and lipoxins of two opposite biological activities, the roles of 15-PGDH in cancer and inflammation are particularly intriguing and challenging. Future investigations in these areas are warranted.

Titin-cap (TCAP) polymorphisms associated with marbling score of beef

Marbling score (MS) is the major qualitative trait that affects carcass quality in beef cattle. In this study, we examined the association between genetic polymorphisms of the titin-cap gene (TCAP) and carcass traits in Korean native cattle (also known as Hanwoo). By direct DNA sequencing in 24 unrelated Korean cattle, we identified five sequence variants in 1.2kb of TCAP. Among them, four common polymorphic sites were selected for genotyping in the beef cattle (n=437). Pair-wise linkage analysis with four polymorphisms showed strong linkage disequilibrium (LD), and three major haplotypes (freq.>0.1) were constructed. Statistical analysis revealed that polymorphisms in intron1 (g.346G>A) and exon2 (g.592-597CTGCAG[Leu-Gln]insdel) showed significant association with marbling score (P(cor.)=0.003 and 0.02, respectively). One haplotype, ht2[C-G-G-del], also showed significant association with MS (P(cor.)=0.0004). Our findings suggest that polymorphisms in TCAP might be among the important genetic factors involved in carcass quality in beef cattle.

The persistence of humoral and cellular immunities more than three decades after smallpox vaccination

This study assessed the persistence of humoral (neutralising antibody titre to vaccinia virus) and cellular (immediate vaccinia-specific interferon (IFN)-gamma-producing T-cell) immunities to smallpox in a Korean population. Individuals who were vaccinated 25-60 years previously had higher neutralising antibody titres (geometric mean titre (GMT) 13.7; 95% CI 11.0-17.2) than vaccinia-naive individuals (GMT 6.7; 95% CI 5.5-8.0; p <0.001). However, there was no significant difference in cellular immunity between individuals vaccinated previously and vaccinia-naive individuals, and only 15% of the individuals vaccinated previously displayed an immediate IFN-gamma-producing effector-memory response in ELISPOT assays.

Cross sections and oscillator strengths for electron-impact excitation of the ÃB11 electronic state of water

The authors report absolute differential and integral cross section measurements for electron-impact excitation of the A (1)B(1) electronic state of water. This is an important channel for the production of the OH (X (2)Pi) radical, as well as for understanding the origin of the atmospheric Meinel [Astrophys. J. 111, 555 (1950)] bands. The incident energy range of our measurements is 20-200 eV, while the angular range of the differential cross section data is 3.5 degrees -90 degrees . This is the first time such data are reported in the literature and, where possible, comparison to existing theoretical work, and new scaled Born cross sections calculated as a part of the current study, is made. The scaled Born cross sections are in good agreement with the integral cross sections deduced from the experimental differential cross sections. In addition they report (experimental) generalized oscillator strength data at the incident energies of 100 and 200 eV. These data are used to derive a value for the optical oscillator strength which is found to be in excellent agreement with that from an earlier dipole (e,e) experiment and an earlier photoabsorption experiment.

Fidelity of implementation in a treatment effectiveness trial of Reconnecting Youth

In 'a treatment effectiveness trial', a program is evaluated in a real-world setting, with an emphasis on achieving high implementation fidelity. Through fidelity assessment, the link between program implementation and outcomes is systematically evaluated and ultimately leads to a greater understanding of program success or failure. This paper reports the results of an implementation fidelity study of the 'Reconnecting Youth' (RY) prevention program. The research questions were (i) was the program implemented with fidelity? and (ii) did better fidelity predict better outcomes? RY is an indicated drug abuse prevention program for high school students that seeks to 'reconnect' high-risk youth to school before they drop out. The results reported here were part of a randomized controlled effectiveness trial of the RY prevention program conducted in two urban school districts in which 15 teachers taught 41 RY classes. Overall, implementation fidelity was high with an average 90% of core lessons being taught. Unexpectedly, increased quality of implementation predicted increased alcohol use and anger. Adherence (teaching more of the curriculum) predicted increased marijuana use, while exposure (student attendance) significantly increased bonding to high-risk peers, alcohol use and anger.

Low energy electron energy-loss spectroscopy of CF3X (X=Cl,Br)

We report threshold electron energy-loss spectra for the fluorohalomethanes CF3X (X=Cl,Br). Measurements were made at incident electron energies of 30 and 100 eV in energy-loss range of 4-14 eV, and at scattering angles of 4 degrees and 15 degrees. Several new electronic transitions are observed which are ascribable to excitation of low-lying states as well as are intrinsically overlapped in the molecules themselves. Assignments of these electronic transitions are suggested. These assignments are based on present spectroscopic and cross-section measurements, high-energy scattering spectra, and ab initio molecular orbital calculations. The calculated potential curves along the C-X bond show repulsive nature, suggesting that these transitions may lead to dissociation of the C-X bond. The present results are also compared with the previous ones for CF3H, CF4, and CF3I.

Metal specificity of an iron-responsive element in Alzheimer's APP mRNA 5'untranslated region, tolerance of SH-SY5Y and H4 neural cells to desferrioxamine, clioquinol, VK-28, and a piperazine chelator

Iron closely regulates the expression of the Alzheimer's Amyloid Precursor Protein (APP) gene at the level of message translation by a pathway similar to iron control of the translation of the ferritin L- and H mRNAs by Iron-responsive Elements in their 5' untranslated regions (5'UTRs). Using transfection based assays in SH-SY5Y neuroblastoma cells we tested the relative efficiency by which iron, copper and zinc up-regulate IRE activity in the APP 5'UTR. Desferrioxamine (high affinity Fe3+ chelator), (ii) clioquinol (low affinity Fe/Cu/Zn chelator), (iii) piperazine-1 (oral Fe chelator), (iv) VK-28 (oral Fe chelator), were tested for their relative modulation of APP 5' UTR directed translation of a luciferase reporter gene. Iron chelation based therapeutic strategies for slowing the progression of Alzheimer's disease (and other neurological disorders that manifest iron imbalance) are discussed with regard to the relative neural toxic action of each chelator in SH-SY5Y cells and in H4 glioblastoma cells.

Clinical characteristics and prognostic factors in diffuse large B-cell lymphoma with bone marrow involvement

7588

Background: Although several studies have been reported about non-Hodgkin’s lymphomas (NHL) with bone marrow (BM) involvement, most of them have not performed immunophenotypic studies and contained heterogeneous NHL histologies. Until now, only a few studies with small sample sizes have been reported about clinical characteristics and prognostic factors in diffuse large B-cell lymphoma (DLBCL) with BM involvement. Methods: Between January 1993 and March 2004, 486 patients were diagnosed with DLBCL. Among 84 DLBCL patients who had BM involvement at initial diagnosis, 9 were not ineligible because of the lack of clinical data or unavailability of BM specimen. So, clinical factors and patterns of BM involvement of 75 patients were analyzed in this study. Results: At initial diagnosis, the median age was 57 years (range: 25∼79). In addition to BM, lymph nodes (76%), spleen (23%), Waldeyer’s ring (19%), gastrointestinal tract (16%), lung/pleura (15%), bone (15%), central nervous system (9%), nasal cavity (8%) and liver (7%) were also involved. Among 75 patients, 67 patients received anthracycline-containing chemotherapy; 4 patients received non-anthracycline-containing chemotherapy and 4 could not receive systemic chemotherapy because of combined medical conditions. The median survival was 32.3 months (5-year overall survival [OS]: 38%). In univariate analysis for prognostic factors, high-intermediate or high international prognostic index (IPI), B-symptoms, leucopenia, anemia, thrombocytopenia, pattern of BM involvement (interstitial or diffuse pattern), > 10% replacement of BM area by lymphoma cells, > 10% of large cell infiltration in BM-involved area by lymphoma at initial diagnosis were associated with poor OS (p < 0.05). Multivariate analysis indicated that > 10% replacement of BM area by lymphoma cells (p < 0.001), peripheral thrombocytopenia (p = 0.001) and high-intermediate or high IPI (p = 0.042) were independent predictors of poor OS. Conclusions: To our knowledge, this is the largest study about DLBCL patients with BM involvement. The BM areas involved by lymphoma cells, peripheral thrombocytopenia and IPI at initial diagnosis are independent prognostic factors in these patients.

No significant financial relationships to disclose.

Preclinical development of a novel inhibitor of oncogenic B-Raf

13056

Background: The discovery of oncogenic B-Raf mutations in a majority of patients with metastatic melanoma, and in many tumors from patients with colorectal cancer and other cancers, presents the opportunity to develop oncogene-selective inhibitors with a favorable safety profile. Methods: Guided by co-crystallography, a novel chemical scaffold has been developed into a series of potent inhibitors of oncogenic B-Raf with selectivity versus wild-type B-Raf. From this series, a potent inhibitor has been chosen as a candidate for development. Results: Consistent with the structure-guided approach, this compound shows pronounced selectivity versus a wide array of over 70 other kinases covering all branches of the kinome. This selectivity translates to a wide cellular therapeutic index: inhibition of proliferation of a panel of cell lines bearing the V600E oncogenic B-Raf mutation occurs at IC50s ranging from 40–400 nM while inhibition of cell lines lacking oncogenic B-Raf occurs at IC50s greater than 6500 nM. This cell-based selectivity for the oncogenic B-Raf is greater than the selectivity shown in biochemical assays, supporting that tumor cells bearing the oncogenic B-Raf protein are more dependent on the MAP kinase pathway. Combination experiments with a series of cytotoxic and targeted clinical anti-cancer agents reveal multiple examples of synergistic inhibition of proliferation in vitro, and this synergy generally appears selectively in oncogenic B-Raf-bearing cells. The good oral bioavailability (F > 70%) allows for prolonged exposure in both rodents and non-rodents. Robust efficacy is evident in a murine COLO205 tumor xenograft model, with once-daily oral dosing at 20 mg/kg over 14 days resulting in > 80% inhibition of tumor growth with no effect on body weight. Conclusions: Since this compound is highly selective and targets a B-Raf variant that is absent in all non-transformed cells, it may have a broad therapeutic index, alone or in combination, for the treatment of patients with V600E oncogenic B-Raf tumors.

[Table: see text]