FasL gene therapy: a new therapeutic modality for head and neck cancer

In this study, we investigated the in vitro and in vivo efficacy of Fas ligand (FasL) gene therapy for the treatment of head and neck cancer. Three head and neck squamous cell carcinoma (HNSCC) cell lines (SCC-1, SCC-12, and SCC-14a) were treated with the Fas agonist CH-11, a monoclonal antibody to the Fas receptor, or with a replication-incompetent adenovirus (AdGFPFasL) expressing a modified murine Fas ligand gene fused to green fluorescent protein (GFP). A replication-incompetent adenovirus containing the GFP gene alone was used as a control for viral transduction toxicity (AdGFP). Cell death was quantified using a tetrazolium-based (MTS) assay. Cells were analyzed by flow cytometry to determine the expression of adenoviral and Fas receptors on the surface of the cells. Our results showed that the head and neck cancer cell lines are resistant to cell death induction when treated with the anti-Fas monoclonal antibody CH-11. This resistance can be overcome with AdGFPFasL, which was able to induce cell death in all three cell lines. Apoptosis induction was demonstrated using Western blotting by evaluating poly(ADP-ribose) polymerase, and caspase 9 cleavages. In addition, intratumoral injections of AdGFPFasL into SCC-14a xenografts induced significant growth suppression of tumors, indicating that FasL gene therapy may provide a new efficient therapeutic modality for HNSCC that is worthy of a clinical trial.     

Modification of estrone at the 6, 16, and 17 positions: novel potent inhibitors of 17beta-hydroxysteroid dehydrogenase type 1

The 17beta-hydroxysteroid dehydrogenases (17beta-HSDs) catalyze the interconversion between the oxidized and reduced forms of androgens and estrogens at the 17 position. The 17beta-HSD type 1 enzyme (17beta-HSD1) catalyzes the reduction of estrone to estradiol and is expressed in malignant breast cells. Inhibitors of this enzyme thus have potential as treatments for hormone dependent breast cancer. Here we report the syntheses and biological evaluation of novel inhibitors based on the estrone or estradiol template. These have been investigated by modification at the 6, 16 or 17 positions or combinations of these in order to gain information about structure-activity relationships by probing different areas in the enzyme active site. Activity data have been incorporated into a QSAR with predictive power, and the X-ray crystal structures of compounds 15 and 16c have been determined. Compound 15 has an IC50 of 320 nM for 17beta-HSD1 and is selective for 17beta-HSD1 over 17beta-HSD2. Three libraries of amides are also reported that led to the identification of inhibitors 19e and 20a, which have IC50 values of 510 and 380 nM respectively, and 20 h which, having an IC50 value of 37 nM, is the most potent inhibitor of 17beta-HSD1 reported to date. These amides are also selective for 17beta-HSD1 over 17beta-HSD2.     

Synergistic effects of peloruside A and laulimalide with taxoid site drugs, but not with each other, on tubulin assembly

Previous studies on the drug content of pelleted tubulin polymers suggest that peloruside A binds in the laulimalide site, which is distinct from the taxoid site. In a tubulin assembly system containing microtubule-associated proteins and GTP, however, peloruside A was significantly less active than laulimalide, inducing assembly in a manner that was most similar to sarcodictyins A and B. Because peloruside A thus far seems to be the only compound that mimics the action of laulimalide, we examined combinations of microtubule-stabilizing agents for synergistic effects on tubulin assembly. We found that peloruside A and laulimalide showed no synergism but that both compounds could act synergistically with a number of taxoid site agents [paclitaxel, epothilones A/B, discodermolide, dictyostatin, eleutherobin, the steroid derivative 17beta-acetoxy-2-ethoxy-6-oxo-B-homo-estra-1,3,5(10)-trien-3-ol, and cyclostreptin]. None of the taxoid site compounds showed any synergism with each other. From an initial study with peloruside A and cyclostreptin, we conclude that the synergism phenomenon derives, at least in part, from an apparent lowering of the tubulin critical concentration with drug combinations compared with single drugs. The apparent binding of peloruside A in the laulimalide site led us to attempt construction of a pharmacophore model based on superposition of an energy-minimized structure of peloruside A on the crystal structure of laulimalide. Although the different sizes of the macrocycles limited our ability to superimpose the two molecules, atom correspondences that were observed were consistent with the difficulty so far experienced in creation of fully active analogs of laulimalide.     

Supporting information technology across health boards in New Zealand: themes emerging from the development of a shared services organization

Shared services organizations are ascribed with adding value to business in several ways but especially by sharing resources and leading to economies of scale. However, these gains are not automatic and in some instances, particularly healthcare, they are difficult to achieve. This article describes a project to develop a shared services information technology infrastructure across two district health boards in New Zealand. The study reveals valuable insight into the crisis issues that accompany change management and identifies emergent themes that can be used to reduce negative impact.     

How safe is safer sex? High levels of HSV-1 and HSV-2 in female sex workers in London

Female sex workers in Europe have low levels of sexually transmitted infections, attributable to condom use. The aim of this paper is to describe the seroepidemiology of HSV-1 and HSV-2 in female sex workers in London by using a 15-year prospective study of 453 sex workers. The seroprevalence of HSV-1 was 74.4% and independently associated with birth in a 'transitional country' (OR 5.4, 95% CI 1.61-18.20). The seroprevalence of HSV-2 was 60% and declined over time; it was also independently associated with time in sex work (OR 2.12, 95% CI 1.23-3.65) and birth in a 'developing country' (OR 2.95, 95% CI 1.34-6.48). We show that a cohort of sex workers with extensive condom use and little known sexually transmitted infection have high levels of HSV-1 and HSV-2 infection, suggesting that condoms may not be universally protective. Sex workers are candidates for HSV vaccine efficacy or intervention studies.     

Injury in Australian veterinarians

BACKGROUND: There are a number of risk factors for traumatic injury in veterinary practice but there is little information on the prevalence of injuries or the factors associated with injury in this profession. AIMS: To identify the prevalence of injuries sustained by veterinarians and the groups most at risk for different types of injury. METHODS: Cross-sectional survey of Australian veterinarians. Subjects were asked whether they had ever had a significant work-related injury, a less serious acute work injury in the last 12 months, a work-related chronic musculoskeletal problem or dog or cat bites. The prevalence of injuries by gender, practice type and decade of graduation were reported and multivariate logistic regression was used to examine the risk of each type of injury. RESULTS: Of 2800 veterinarians, over half (51%) reported a significant work-related injury during their career while 26% of practitioners reported having at least one injury in the previous 12 months. Chronic work-related musculoskeletal problems were reported by 49% of respondents. Dog and cat bites were also very common. After adjusting for graduation year and university, males were more likely than females to have experienced cat or dog bites or have a chronic or significant injury, and large animal veterinarians were most likely to have chronic or significant injuries. CONCLUSIONS: A high injury prevalence was found among Australian veterinarians with large animal practitioners at highest risk. This is the largest study of Australian veterinarians to have been reported and has shown that injuries are common and serious in the profession.     

Enhancement of the infectivity of SARS-CoV in BALB/c mice by IMP dehydrogenase inhibitors, including ribavirin

Because of the conflicting data concerning the SARS-CoV inhibitory efficacy of ribavirin, an inosine monophosphate (IMP) dehydrogenase inhibitor, studies were done to evaluate the efficacy of ribavirin and other IMP dehydrogenase inhibitors (5-ethynyl-1-beta-D-ribofuranosylimidazole-4-carboxamide (EICAR), mizoribine, and mycophenolic acid) in preventing viral replication in the lungs of BALB/c mice, a replication model for severe acute respiratory syndrome (SARS) infections (Subbarao, K., McAuliffe, J., Vogel, L., Fahle, G., Fischer, S., Tatti, K., Packard, M., Shieh, W.J., Zaki, S., Murphy, B., 2004. Prior infection and passive transfer of neutralizing antibody prevent replication of severe acute respiratory syndrome coronavirus (SARS-CoV) in the respiratory tract of mice. J. Virol. 78, 3572-3577). Ribavirin given at 75 mg/kg 4 h prior to virus exposure and then given twice daily for 3 days beginning at day 0 was found to increase virus lung titers and extend the length of time that virus could be detected in the lungs of mice. Other IMP dehydrogenase inhibitors administered near maximum tolerated doses using the same dosing regimen as for ribavirin were found to slightly enhance virus replication in the lungs. In addition, ribavirin treatment seemed also to promote the production of pro-inflammatory cytokines 4 days after cessation of treatment, although after 3 days of treatment ribavirin inhibited pro-inflammatory cytokine production in infected mice, significantly reducing the levels of the cytokines IL-1alpha, interleukin-5 (IL-5), monocyte chemotactic protein-1 (MCP-1), and granulocyte-macrophage colony stimulating factor (GM-CSF). These findings suggest that ribavirin may actually contribute to the pathogenesis of SARS-CoV by prolonging and/or enhancing viral replication in the lungs. By not inhibiting viral replication in the lungs of infected mice, ribavirin treatment may have provided a continual source of stimulation for the inflammatory response thought to contribute to the pathogenesis of the infection. Our data do not support the use of ribavirin or other IMP dehydrogenase inhibitors for treating SARS infections in humans.     

Sperm immobilization by sera from unimmunized guinea pigs: requirements for immunoglobulin and complement

The components in serum from non-immunized guinea pigs responsible for the immunological immobilization of human spermatozoa have been elucidated. Heating the serum at 56°C for 30 min, pretreatng the serum with purified cobra venom factor or the inclusion aggregated human IgG in the immobilization test all eliminated its immobilizing capacity, suggesting the involvement of complement in this process. Using purified guinea pigs components, it was established that complement components C1-9 as well as guinea pig IgG were required for immobilization. Rabbit IgG, but not human IgG, could be substituted for guinea pig IgG without affecting the degree of immobilization. Absorption of guinea pig IgG with human spermatoza to its addition to C1-9 and motile spermatoza led to the loss of all immobilizing activity. Thus, it appears that ‘natural’ antibody to spermatoza plus all nine complements are required for sperm immobilization.