Numerical solution of the Gross-Pitaevskii equation using an explicit finite-difference scheme: An application to trapped Bose-Einstein condensates

A fast, explicit time-marching scheme is used for the solution of the Gross-Pitaevskii equation in cylindrical geometry. Scheme validity is analyzed using simple analytical tests and is demonstrated for two situations of physical interest on the Bose-Einstein condensation (BEC) of trapped alkali-metal vapors. This is tested using reproduced results on the free expansion of a BEC after removing a cylindrical trap

High prevalence of antibodies to human herpesvirus 8 in relatives of patients with classic Kaposi's sarcoma from Sardinia

A survey for antibodies to a recombinant small viral capsid antigen (sVCA) of human herpesvirus type 8 (HHV‐8) was conducted in Sardinia, one of the world's highest incidence areas for classic Kaposi's sarcoma (KS). Prevalence of antibodies to HHV‐8 sVCA was greatest in patients with KS (95%), followed by family members (39%) and a Sardinian control population age‐ and sex‐matched to the relatives (11%). Within families, prevalence of antibodies was about equal among spouses, children, and siblings of KS patients, a finding that raises the possibilities of intrafamilial person‐to‐person or vertical transmission. Antibodies were detected 2–3 times more frequently in males than in females. The data show that prevalence of antibodies to HHV‐8 sVCA correlates with the distribution of classic KS in a high‐ incidence area. Clustering of seroprevalence within some families suggests the presence of familial risk factors for active HHV‐8 infection

Honokiol, a Small Molecular Weight Natural Product, Inhibits Angiogenesis in Vitro and Tumor Growth in Vivo

Natural products comprise a major source of small molecular weight angiogenesis inhibitors. We have used the transformed endothelial cell line SVR as an effective screen of natural product extracts to isolate anti-angiogenesis and anti-tumor compounds. Aqueous extracts of Magnolia grandiflora exhibit potent activity in our SVR proliferation assays. We found that the small molecular weight compound honokiol is the active principle of magnolia extract. Honokiol exhibited potent anti-proliferative activity against SVR cells in vitro. In addition, honokiol demonstrated preferential inhibition of primary human endothelial cells compared with fibroblasts and this inhibition was antagonized by antibodies against TNF alpha-related apoptosis-inducing ligand. In vivo, honokiol was highly effective against angiosarcoma in nude mice. Our preclinical data suggests that honokiol is a systemically available and non-toxic inhibitor of angiogenesis and should be further evaluated as a potential chemotherapeutic agent

From coherent to incoherent dynamical behaviour of quantum atomic gases in periodic potentials

In seminal experiments performed in 1995, alkali atomic gases have been cooled to nanokelvin temperatures to form a new state of matter which shows macroscopic quantum coherence and Bose-Einstein condensation. We give a physics-oriented view of diverse transport behaviours of these Bose-Einstein condensates, which can be explored after solving a nonlinear Schrodinger equation by means of an explicit time-marching algorithm. Coherent and decoherent transport behaviour in periodic potentials is reviewed and new aspects related to chaotic nonlinear dynamics are anticipated

Numerical solution of the stationary Gross-Pitaevskii equation: tests of a combined imaginary-time-marching technique with splitting

Motivated by current experimental and theoretical activity in the field of Bose-Einstein condensation of trapped vapours of alkali atoms, we implement the calculation of the ground-state energy and wave function of a dilute interacting condensate confined by a three-dimensional external potential with cylindrical symmetry. To this purpose we solve in imaginary time the non-linear Schrödinger equation governing the dynamics of the condensate wave function by a splitting of the nonlinear term. The good and the bad of the method are analyzed by testing the simulation results against the textbook properties of stationary states. The latter are determined by using an explicit time-marching technique previously developed and successfully used to study the transport behaviour of such systems

Transcriptional Downregulation of ORF50/Rta by Methotrexate Inhibits the Switch of Kaposi's Sarcoma-Associated Herpesvirus/Human Herpesvirus 8 from Latency to Lytic Replication

Kaposi's sarcoma-associated herpesvirus (KSHV) encodes a cellular dihydrofolate reductase (DHFR) homologue. Methotrexate (MTX), a potent anti-inflammatory agent, inhibits cellular DHFR activity. We investigated the effect of noncytotoxic doses of MTX on latency and lytic KSHV replication in two KSHV-infected primary effusion lymphoma cell lines (BC-3 and BC-1) and in MTX-resistant BC-3 cells (MTX-R-BC-3 cells). Treatment with MTX completely prevented tetradecanoyl phorbol acetate-induced viral DNA replication and strongly decreased viral lytic transcript levels, even in MTX-resistant cells. However, the same treatment had no effect on transcription of cellular genes and KSHV latent genes. One of the lytic transcripts inhibited by MTX, ORF50/Rta (open reading frame), is an immediate-early gene encoding a replication-transcription activator required for expression of other viral lytic genes. Therefore, transcription of genes downstream of ORF50/Rta was inhibited, including those encoding the viral G-protein-coupled receptor (GPCR), viral interleukin-6, and K12/kaposin, which have been shown to be transforming in vitro and oncogenic in mice. Resistance to MTX has been documented in cultured cells and also in patients treated with this drug. However, MTX showed an inhibitory activity even in MTX-R-BC-3 cells. Two currently available antiherpesvirus drugs, cidofovir and foscarnet, had no effect on the transcription of these viral oncogenes and ORF50/Rta. MTX is the first example of a compound shown to downregulate the expression of ORF50/Rta and therefore prevent viral transforming gene transcription. Given that the expression of these genes may be important for tumor development, MTX could play a role in the future management of KSHV-associated malignancies

PCR analysis of <i>Mycoplasma fermentans</i> and <i>M. penetrans</i> in classic Kaposi’s sarcoma

Kaposi’s sarcoma (KS) is a multicentric vascular neoplasia characterized by macules, nodules and angiomatoid plaques mainly present on the skin surface. Four KS variants are recognized: classic or Mediterranean; endemic or African; the variant following on renal transplant or immunosuppressive therapy; and, lastly, the epidemic or AIDS-associated variant. The variants differ in the sites involved, course of the disease and in their prognosis. Genetic, immunological, environmental and viral factors have proven to be relevant in the aetiology and pathogenesis of all KS variants. In addition, further possible interacting factors such as mycoplasma infections have come to attention for the single variants