The prognosis of malignant gliomas remains dismal and alternative therapeutic strategies are required. Immunotherapy with dendritic cells (DCs) pulsed with tumour antigens emerges as a promising approach. Many parameters influence the efficacy of DC-based vaccines and need to be optimised in preclinical models. The present study compares different vaccine schedules using DCs loaded with tumour cell lysate (DC-Lysate) for increasing long-term survival in the GL26 orthotopic murine glioma model, focusing on the number of injections and an optimal way to recall antitumour immune response. Double vaccination with DC-Lysate strongly prolonged median survival compared to unvaccinated animals (mean survival 87.5 days vs. 25 days; p < 0.0001). In vitro data showed specific cytotoxic activity against GL26. However, late tumour relapses frequently occurred after 3 months and only 20% of mice were finally cured at 7 months. While one, two or three DC injections gave identical survival, a boost using only tumour lysate after initial DC-Lysate priming dramatically improved long-term survival in vaccinated mice, compared to the double DC-Lysate group, with 67.5% of animals cured at 7 months (p < 0.0001). In vitro data showed better specific CTL response and also the induction of specific anti-GL26 antibodies in the DC-Lysate/Lysate group, which mediated Complement Dependent Cytotoxicity. These experimental data may be of importance for the design of clinical trials that currently use multiple DC injections.

Delayed pubertal development and low fertility of Bos indicus x Bos taurus crossbred male cattle and domestic buffaloes is hardly understood hence, a sensitive enzymeimmunoassay (EIA) was developed using the second antibody-coating technique and testosterone-3-O-carboxymethyloxime-horseradish peroxidase conjugate as a label for determination of testosterone in blood plasma. The EIA was validated by standard criteria. Blood samples were collected by venipuncture from growing male cattle (Karan Fries and Sahiwal) and buffalo (Murrah) and testosterone was estimated using the EIA procedure. Plasma testosterone concentrations increased significantly (P < 0.05) with advancing age. Testosterone concentrations were significantly (P < 0.01) higher in Sahiwal males in comparison to Karan Fries males. The low testosterone levels in crossbred than Sahiwal could imply that crossbred males have either not stabilized genetically or not adapted well in Indian climatic conditions resulting in poor libido and poor semen quality. The low testosterone levels in Murrah buffalo males may be the possible reason for delayed maturity in this species. The direct, sensitive EIA validated for estimating the plasma testosterone concentration was reliable for studying the testosterone profile in blood plasma of males. The results suggest that there could be a requirement for higher testosterone secretion by males during early stages of growth for attaining early sexual maturity.