|
OPEN ACCESS PLUS
Accepted articles are published online for free open access for all to view. Open access publishing provides the maximum dissemination of the article to the largest audience. Authors must pay for this service. All corresponding authors will be asked to indicate whether or not they wish to pay to have their paper made freely available on publication. If authors do not select the Open Access option, then their article will be published with standard subscription-based access at no charge.
Authors who opt for Open Access Plus may also self-archive publishers postprints. Bentham Science is compliant with the open access policy for the MRC, Cancer Research UK, NIH, and many other funders. For details, refer to http://www.benthamscience.com/permission.php or email to; openaccess@benthamscience.org.
Contents
4(3): Pp. 195 - 204
S. Bellino, V. Francavilla, O. Longo, A. Tripiciano, G. Paniccia, A. Arancio, V. Fiorelli, A. Scoglio, B. Collacchi, M. Campagna, A. Lazzarin, G. Tambussi, C. Tassan Din, R. Visintini, P. Narciso, A. Antinori, G. D'Offizi, M. Giulianelli, M. Carta, A. Di Carlo, G. Palamara, M. Giuliani, M. E. Laguardia, P. Monini, M. Magnani, F. Ensoli and B. Ensoli
[Open Access Plus] |
|
The native HIV-1 Tat protein was chosen as vaccine candidate for phase I clinical trials in both uninfected (ClinicalTrials.gov identifier: NCT00529698) and infected volunteers (ClinicalTrials.gov identifier: NCT00505401). The rationale was based on the role of Tat in the natural infection and AIDS pathogenesis, on the association of Tat-specific immune responses with the asymptomatic stage and slow-progression rate as well as on its sequence conservation among HIV clades (http://www.hiv1tat-vaccines.info/). The parallel conduction in the same clinical centers of randomized, double blind, placebo-controlled phase I studies both in healthy, immunologically competent adults and in HIV-infected, clinically asymptomatic, individuals represents a unique occasion to compare the vaccine-induced immune response in both the preventive and therapeutic setting. In both studies, the same lot of the native Tat protein was administered 5 times, every four weeks, subcute (SC) with alum adjuvant or intradermic (ID), in the absence of adjuvant, at 7.5 ig, 15 ig or 30 ig doses, respectively. The primary and secondary endpoints of these studies were the safety and immunogenicity of the vaccine candidate, respectively. The study lasted 52 weeks and monitoring was conducted for on additional 3 years. The results of both studies indicated that the Tat vaccine is safe and well tolerated both locally and systemically and it is highly immunogenic at all the dosages and by both routes of administration. Vaccination with Tat induced a balanced immune response in uninfected and infected individuals. In particular, therapeutic immunization induced functional antibodies and partially reverted the marked Th1 polarization of anti-Tat immunity seen in natural infection, and elicited a more balanced Th1/Th2 immune response. Further, the number of CD4 T cells correlated positively with anti-Tat antibody titers. Based on these results, a phase II study is ongoing in infected drug-treated individuals (http://www.hiv1tat-vaccines.info/).
|
3(3): Pp. 228 - 231
Akio Sakamoto and Yukihide Iwamoto
[Open Access Plus] |
|
Osteosarcoma is the most common primary bone tumor in childhood and adolescence. The use of combination chemotherapy and surgery enables long-term survival in approximately 60-70% of cases. However, the necessity for surgery, the poor prognosis of patients with metastatic or recurrent disease (long-term survival in only about 20% of cases), and the lack of establishment of second-line chemotherapy suggest that improvements in chemotherapy are desperately needed. Currently, in an effort to extend the protocol with the chemotherapy drugs that already exist, high-dose chemotherapy with/without autologous peripheral blood stem cell transplantation, and tumor-targeted drug delivery systems are under investigation. Future drug developments will no doubt lie in the direction of immunotherapy and anti-angiogenic therapy, as well as the use of cytotoxic drugs. Identifying the genes and signal transduction pathways responsible for the development of osteosarcoma or for the occurrence of malignancy in cases of osteosarcoma will undoubtedly lead to the identification of pathway-specific agents, or possible gene therapy. Furthermore, as increased light is shed on the character of osetoblastic differentiation in osteosarcoma, this will certainly give rise to new treatments utilizing differentiation therapy. This article reviews the current status and perspectives regarding the treatment of osteosarcoma in terms of chemotherapy.
|
3(2): Pp. 89 - 96
Andrew Knight
[Open Access Plus] |
|
Widespread reliance on animal models during preclinical research and toxicity testing assumes their reasonable predictivity for human outcomes. However, of 20 published systematic reviews examining human clinical utility, located during a comprehensive literature search, animal models demonstrated significant potential to contribute toward the development of clinical interventions in only two cases, one of which was contentious. Included were experiments expected by ethics committees to lead to medical advances, highlycited experiments published in major journals, and chimpanzee experiments — the species most generally predictive of human outcomes. Seven additional reviews failed to demonstrate utility in reliably predicting human toxicological outcomes such as carcinogenicity and teratogenicity. Results in animal models were frequently equivocal, or inconsistent with human outcomes. Consequently, animal data may not generally be considered useful for these purposes. Regulatory acceptance of non-animal models is normally conditional on formal scientific validation. In contrast, animal models are simply assumed to be predictive of human outcomes. These results demonstrate the invalidity of such assumptions. The poor human clinical and toxicological utility of animal models, combined with their generally substantial animal welfare and economic costs, necessitate considerably greater rigor within animal studies, and justify a ban on the use of animal models lacking scientific data clearly establishing their human predictivity or utility.
|
2(3): Pp. 182 - 190
William C. Olson, Warren D.W. Heston and Ayyappan K. Rajasekaran
[Open Access Plus] |
|
Prostate cancer is the most common non-cutaneous cancer of men in the United States and represents their second-leading cause of cancer-related death. Metastatic disease is largely resistant to conventional chemotherapies, and targeted therapies are urgently needed. Prostate-specific membrane antigen (PSMA) is a prototypical cell-surface marker of prostate cancer. PSMA is an integral, nonshed, type 2 membrane protein with abundant and nearly universal expression in prostate carcinoma, but has limited extra-prostatic expression. In addition, PSMA is expressed in the neovasculature of other solid tumors. These findings have spurred development of PSMA-targeted therapies for cancer, and first-generation products have entered clinical testing. Vaccine approaches have included recombinant protein, nucleic acid and cell-based strategies, and anti-PSMA immune responses have been demonstrated in the absence of significant toxicity. Therapy with drug-conjugated and radiolabeled antibodies has yielded objective clinical responses as measured by reductions in serum prostate-specific antigen and/or imageable tumor volume. However, responses were observed in a minor fraction of patients and at doses near the maximum tolerated dose. Overall, these initial studies have provided measured proof of concept for PSMAbased therapies, and second-generation antibody and vaccine products may hold the key to exploit PSMA for molecularly targeted therapy of prostate and other cancers.
|
|
