Hadronic Spectral Function and Charm Meson Production

At the chiral restoration/deconfinement transition, most hadrons undergo a Mott transition from being bound states in the confined phase to resonances in the deconfined phase. We investigate the consequences of this qualitative change in the hadron spectrum on final state interactions of charmonium in hot and dense matter, and show that the Mott effect for D-mesons leads to a critical enhancement of the J/Psi dissociation rate. Anomalous J/Psi suppression in the NA50 experiment is discussed as well as the role of the Mott effect for the heavy flavor kinetics in future experiments at the LHC. The status of our calculations of hadron-hadron cross sections using the quark interchange and chiral Lagrangian approaches is reviewed, and an Ansatz for a unification of these schemes is given.Comment: 12 pages, 6 figures, Proceedings of the Budapest'02 Workshop on Quark & Hadron Dynamics, Budapest, Hungary, March 3-7, 200

Antiangiogenic properties of a nutrient mixture in a model of hemangioma

The pathogenesis of hemangiomas is still largely unknown and the current therapy, such as systemic corticosteroid, vincristine, and interferon-alpha, is toxic and remains unsatisfactory. A nutrient mixture (NM) containing lysine, proline, ascorbic acid and green tea extract has shown significant anti-angiogenic and anti-tumor effect against a number of cancer cell lines. Aim: Using a mouse hemangioendothelioma model, we investigated the efficacy of NM. We also tested the effect of NM in vitro, evaluating cell viability, MMP secretion, invasion, morphology and apoptosis. Methods: Athymic nude mice, 5–6 weeks old, were inoculated with 3 x106 EOMA cells subcutaneously and randomly divided into two groups; group A was fed a regular diet and group B — a regular diet supplemented with 0.5% NM. Four weeks later, the mice were sacrificed and their tumors were excised, weighed and processed for histology. We also tested the effect of NM in vitro. Results: NM inhibited the growth of tumors by 50%. In vitro, NM exhibited dose response cytotoxicity with 10%, 30% and 55% at 10, 100 and 1000 μg/ml. Invasion through Matrigel was inhibited at 50, 100 and 500 μg/ml by 25%, 30% and 100% respectively. NM induced dose-dependent apoptosis of EOMA cells. Conclusions: These results suggest that NM may have therapeutic potential in treating infantile hemangioendotheliomas and, perhaps, other cutaneous vascular tumors

In vivo and In vitro effect of a nutrient mixture on human hepatocarcinoma cell line SK-HEP-1

Long-term survival of patients with hepatocellular carcinoma (HCC), a common cancer worldwide, remains poor, due to metastasis and recurrence. Aim: To investigate the effect of a novel nutrient mixture (NM) containing ascorbic acid, lysine, proline, and green tea extract on human HCC cell line Sk-Hep-1 In vivo and In vitro. Methods: After one week of isolation, 5–6 week old male athymic nude mice were inoculated with 3 x 106 SK-Hep-1 cells subcutaneously and randomly divided into two groups; group A was fed a regular diet and group B a regular diet supplemented with 0.5% NM. Four weeks later, the mice were sacrificed and their tumors were excised, weighed and processed for histology. We also tested the effect of NM In vitro on SK-Hep-1 cells, measuring cell proliferation by MTT assay, invasion through Matrigel, apoptosis by green caspase detection kit, MMP secretion by zymography, and morphology by H&E staining. Results: NM inhibited tumor weight and burden of SK-Hep-1 xenografts by 42% and 33% respectively. In vitro, NM exhibited 33% toxicity over the control at 500 and 1000 μg/ml concentration. Zymography demonstrated MMP-2 and MMP-9 secretion which was inhibited by NM in a dose dependent fashion, with virtual total inhibition at 1000 μg/ml. Invasion through Matrigel was inhibited at 100, 500 and 1000 μg/ml by 53%, 83% and 100% respectively. NM induced slight apoptosis at 100 μg/ml, and profound apoptosis at 500 μg/ml and 1000 μg/ml concentration. Conclusions: These results suggest that NM has therapeutic potential in treatment of HCC

Mott Effect and J/Psi Dissociation at the Quark-Hadron Phase Transition

We investigate the in-medium modification of pseudoscalar and vector mesons in a QCD motivated chiral quark model by solving the Dyson-Schwinger equations for quarks and mesons at finite temperature for a wide mass range of meson masses, from light (pi, rho) to open-charm (D, D*) states. At the chiral / deconfinement phase transition, the quark-antiquark bound states enter the continuum of unbound states and become broad resonances (the hadronic Mott effect). We calculate the in-medium cross sections for charmonium dissociation due to collisions with light hadrons in a chiral Lagrangian approach, and show that the D and D* meson spectral broadening lowers the threshold for charmonium dissociation by pi and rho meson impact. This leads to a step-like enhancement in the reaction rate. We suggest that this mechanism for enhanced charmonium dissociation may be the physical mechanism underlying the anomalous J/Psi suppression observed by NA50.Comment: 3 pages, 3 figures, uses EPJ style (included), contribution to the Proceedings of the International Conference on Quark Nuclear Physics, June 9 - 14, 2002, Juelich, Germany; 1 figure added, text adde

Ascorbate depletion increases growth and metastasis of melanoma cells in vitamin C deficient mice

Aim: Our main objective was to determine the effect of ascorbate supplementation in mice unable to synthesize ascorbic acid (gulo KO) when challenged with murine B16FO cancer cells. Methods: Gulo KO female mice 36–40 weeks of age were deprived of or maintained on ascorbate in food and water for 4 weeks prior to subcutaneous injection of 2.5×106 B16FO murine melanoma cells in the right flank of mice. A control group of wild type mice were also injected with the melanoma cells and maintained on a regular murine diet. Mice were continued on their respective diets for another 2 weeks after injection. The mice were then sacrificed, blood was drawn and their tumors were measured, excised and processed for histology. Results: Mean weight of animals decreased significantly (30%, p < 0.0001) in the ascorbate-restricted group but increased slightly, but insignificantly, in the ascorbate-supplemented group. The mean tumor weight in ascorbate supplemented mice was significantly reduced (by 64%, p = 0.004) compared to tumor weight in ascorbate-deprived gulo mice. The mean tumor weight of wild type mice did not differ significantly from the ascorbate-supplemented mice. Gulo KO mice supplemented with ascorbate developed smaller tumors with more collagen encapsulation and fibrous capsule interdigitation, while gulo KO mice deprived of ascorbate hosted large tumors with poorly defined borders, showing more necrosis and mitosis. Ascorbate supplementation of gulo KO mice resulted in profoundly decreased serum inflammatory cytokine IL-6 (90% decrease, p = 0.04) and IL-1β (62% decrease) compared to the levels in gulo KO mice deprived of ascorbate. Conclusion: Ascorbate supplementation modulated tumor growth and inflammatory cytokine secretion as well as enhanced encapsulation of tumors in scorbutic mice

f [N pi N]: from quarks to the pion derivative coupling

We study the N pi N coupling, in the framework of a QCD-inspired confining Nambu-Jona-Lasinio model. A simple relativistic confining and instantaneous quark model is reviewed. The Salpeter equation for the nucleon and the boosted pion is solved. The f [n pi n] and f[n pi Delta] couplings are calculated and they turn out to be reasonably good. The sensibility of f[n pi n] and f[n pi Delta] to confinement, chiral symmetry breaking and Lorentz invariance is briefly discussed.Comment: 30 pages in LaTex RevTex, 6 postscript figure

A nutrient mixture inhibits glioblastoma xenograft U-87 MG growth in male nude mice

Background: Brain tumors are highly aggressive tumors characterized by secretions of high levels of matrix metalloproteinase-2 and -9, leading to tumor growth, invasion and metastasis by digesting the basement membrane and extracellular matrix components. We previously demonstrated the effectiveness of a nutrient mixture (NM) containing ascorbic acid, lysine, proline, and green tea extract in vitro: on activity of urokinase plasminogen activator, matrix metalloproteinases and TIMPs in various human glioblastoma (LN-18, T-98G and A-172) cell lines and on glioblastoma A-172 cell proliferation and Matrigel invasion. Aim: Our main objective in this study was to investigate the effect of the NM in vivo on human glioblastoma U-87 MG cell line. Materials and Methods: Athymic male nude mice inoculated with 3·106 U-87 MG cells subcutaneously and were fed a regular diet or a regular diet supplemented with 0.5% NM. Four weeks later, the mice were sacrificed, the tumors were weighed and measured. The samples were studied histologically. Results: NM inhibited tumor weight and tumor burden by 53% (p = 0.015) and 48% (p = 0.010), respectively. Conclusions: These results suggest the therapeutic potential of NM as an adjuvant in the treatment of glioblastoma

Effective restoration of chiral and axial symmetries at finite temperature and density

The effective restoration of chiral and axial symmetries is investigated within the framework of the SU(3) Nambu-Jona-Lasinio model. The topological susceptibility, modeled from lattice data at finite temperature, is used to extract the temperature dependence of the coupling strength of the anomaly. The study of the scalar and pseudoscalar mixing angles is performed in order to discuss the evolution of the flavor combinations of $q \bar q$ pairs and its consequences for the degeneracy of chiral partners. A similar study at zero temperature and finite density is also realized.Comment: 5 pages, 1 figure. Talk given at Strange Quark Matter 2004, Cape Town, South Africa, 15-20 September, 200