Showing papers by "Robert M. Grant published in 2008"

Whither or wither microbicides

Abstract: After disappointing results from all efficacy trials conducted to date, the field of microbicides research now faces substantial challenges. Poor coordination among interested parties and the choice of nonvalidated scientific targets for phase III studies have hampered progress and created mistrust about the use of microbicides as a method to prevent HIV-1 sexual transmission. Although new promising strategies are available, there will need to be serious reappraisals of how decisions are made to advance the next generations of candidates into clinical trials, and the use of appropriate animal models in this process will be critical.

Chemotherapeutic wafers for High Grade Glioma.

Abstract: BACKGROUND Standard treatment for high grade glioma (HGG) usually entails biopsy or surgical resection where possible followed by radiotherapy. Systemic chemotherapy is usually only given in selected cases and its use is often limited by side effects. Implanting wafers impregnated with chemotherapy agents into the resection cavity represents a novel means of delivering drugs to the central nervous system (CNS) with fewer side effects. It is not clear how effective this modality is or whether it should be recommended as part of standard care for HGG. OBJECTIVES To assess whether chemotherapeutic wafers have any advantage over conventional therapy for HGG. SEARCH STRATEGY The following databases were searched: The Cochrane Central Register of Controlled Trials (CENTRAL), Issue 2, 2007, MEDLINE, EMBASE, SCIENCE CITATION INDEX, Physician Data Query and the meta-Register of Controlled Trials. Reference lists of all identified studies were searched. The Journal of Neuro-Oncology was hand searched from 1999 to 2007, including all conference abstracts. Neuro-oncologists were contacted regarding ongoing and unpublished trials. SELECTION CRITERIA Patients included those of all ages with a presumed diagnosis of malignant glioma from clinical examination and radiology. Interventions included insertion of chemotherapeutic wafers to the resection cavity at either primary surgery or for recurrent disease. Included studies had to be randomised controlled trials (RCTs). DATA COLLECTION AND ANALYSIS Quality assessment and data extraction were undertaken by two review authors. Outcome measures included survival, time to progression, quality of life (QOL) and adverse events. MAIN RESULTS In primary disease two RCTs assessing the effect of carmustine impregnated wafers (Gliadel(R)) and enrolling a total of 272 participants were identified. Survival was increased (hazard ratio (HR) 0.65 confidence interval (CI) 0.48 to 0.86 p = 0.003). In recurrent disease a single RCT was included assessing the effect of Gliadel(R) and enrolling 222 participants. It did not demonstrate a significant survival increase (HR 0.83 CI 0.62 to 1.10 p = 0.2). There was no suitable data for time to progression or QOL. Adverse events were not more common in either arm, and were presented in a descriptive fashion. AUTHORS' CONCLUSIONS Gliadel(R) results in a prolongation of survival without an increased incidence of adverse events when used as primary therapy. There is no evidence of enhanced progression free survival (PFS) or QOL. In recurrent disease, Gliadel(R) does not appear to confer any added benefit. These findings are based on the results of three RCTs with approximately 500 patients in total.

Potentially Exposed but Uninfected Individuals Produce Cytotoxic and Polyfunctional Human Immunodeficiency Virus Type 1-Specific CD8+ T-Cell Responses Which Can Be Defined to the Epitope Level

Abstract: We measured CD8(+) T-cell responses in 12 potentially exposed but uninfected men who have sex with men by using cytokine flow cytometry. Four of the individuals screened exhibited polyfunctional immune responses to human immunodeficiency virus type 1 Gag or Vif. The minimum cytotoxic T lymphocyte epitope was mapped in one Gag responder.

Frequent international travel by men who have sex with men recently diagnosed with HIV-1: potential for transmission of primary HIV-1 drug resistance.

Abstract: We assessed the potential for international transmission of primary drug resistance among men who have sex with men newly diagnosed with human immunodeficiency virus (HIV) (n= 64) during the period in which they were unaware of their infection. During their exposure period, 55% of participants lived or traveled outside of the United States, and 59% had foreign-born sexual partners. Eighteen participants (28%) were classified as recently infected with HIV. Primary HIV-1 drug resistance was detected in eight participants (13%), four of whom were recently infected. Given the high frequency of international travel and prevalence of primary HIV-1 drug resistance among study participants, prevention strategies should incorporate specific counseling on risk of cross-border transmission.

Immunity to HIV-1 is influenced by continued natural exposure to exogenous virus.

Abstract: Unprotected sexual intercourse between individuals who are both infected with HIV-1 can lead to exposure to their partner's virus, and potentially to super-infection. However, the immunological consequences of continued exposure to HIV-1 by individuals already infected, has to our knowledge never been reported. We measured T cell responses in 49 HIV-1 infected individuals who were on antiretroviral therapy with suppressed viral loads. All the individuals were in a long-term sexual partnership with another HIV-1 infected individual, who was either also on HAART and suppressing their viral loads, or viremic (>9000 copies/ml). T cell responses to HIV-1 epitopes were measured directly ex-vivo by the IFN-gamma enzyme linked immuno-spot assay and by cytokine flow cytometry. Sexual exposure data was generated from questionnaires given to both individuals within each partnership. Individuals who continued to have regular sexual contact with a HIV-1 infected viremic partner had significantly higher frequencies of HIV-1-specific T cell responses, compared to individuals with aviremic partners. Strikingly, the magnitude of the HIV-1-specific T cell response correlated strongly with the level and route of exposure. Responses consisted of both CD4(+) and CD8(+) T cell subsets. Longitudinally, decreases in exposure were mirrored by a lower T cell response. However, no evidence for systemic super-infection was found in any of the individuals. Continued sexual exposure to exogenous HIV-1 was associated with increased HIV-1-specific T cell responses, in the absence of systemic super-infection, and correlated with the level and type of exposure.