Anti-idiotypic antibody and recombinant antigen vaccines in colorectal cancer patients.

The colorectal carcinoma (CRC)-associated GA733 antigen (also known as CO17-1A, KS1-4, KSA or EpCAM) has been the target of a phase II/III randomized trial of passive immunotherapy with monoclonal antibody CO17-1A and phase I active immunotherapy trials with polyclonal anti-idiotypic antibodies mimicking the CO17-1A or GA733 epitope on the antigen. The CO17-1A antigen was molecularly cloned and the extracellular domain expressed in baculovirus (BV) GA733-2E. Whereas, anti-idiotypic antibody mimics a single epitope on the antigen, BV GA733-2E expresses multiple potentially immunogenic epitopes. In animals, the immunogenicity of BV GA733-2E in aluminum hydroxide was superior to that of anti-idiotype in the same adjuvant. Here, we compared the immunogenicity of anti-idiotypic antibody and GA733-2E antigen in CRC patients. These studies indicate that the antigen is superior to the anti-idiotype antibody in inducing humoral and cellular immunity in CRC patients.

Immunogenicity of recombinant GA733-2E antigen (CO17-1A, EGP, KS1-4, KSA, Ep-CAM) in gastro-intestinal carcinoma patients.

Targeting the GA733 antigen (also known as CO17-1A, EGP, KS1-4, KSA, Ep-CAM) by monoclonal antibody CO17-1A or anti-idiotypic antibodies mimicking the CO17-1A or GA733 epitope has induced prolonged survival and specific immune responses to the antigen, respectively, in colorectal cancer (CRC) patients. In pre-clinical studies in mice and rabbits, recombinant baculovirus-derived GA733-2E antigen was superior to anti-idiotypic antibodies at modulating specific immune responses. Our aim was to evaluate the immunogenicity and potential toxicity of alum-precipitated GA733-2E in a phase I trial in patients with resected CRC or pancreatic cancer. Six patients with advanced pancreatic carcinoma and 6 with CRC Dukes' stage A, B or C received between 4 and 7 doses of alum-precipitated GA733-2E at 50, 200 or 800 microg/dose at monthly intervals. Antibody binding to GA733-2E or antigen-positive CRC cells was determined, as were antigen-specific proliferative, cytolytic T-lymphocyte and delayed-type hypersensitivity responses. Six of the 12 patients developed antigen-specific humoral immune responses after immunotherapy, and 8 developed cellular immune responses. The overall immune response rate, including patients with humoral and/or cellular immune responses, was 83%. Median overall survival of the CRC and pancreatic cancer patients was 39.8 and 11.2 months, respectively. Following 18 years of single-epitope targeting of the GA733 antigen, immunization of patients against multiple epitopes of the antigen frequently induces an immune response in the absence of significant toxicity, despite relatively widespread expression of this antigen on normal epithelial cells.

Electron microscopic findings in faeces from children with gastroenteritis.

A total of 788 faecal samples from children in the Wellington region with symptoms of gastroenteritis were examined by immune electron microscopy. Virus was seen in 211 specimens; 87% of these were from infants less than three years of age. A viral diagnosis was made in 27% of cases consisting of rotaviruses (19%), adenoviruses (5%), and small round viruses (3%). Both rotaviruses and adenoviruses were most prevalent during the winter months, while the small round viruses peaked in summer and winter. The importance of fastidious adenoviruses is illustrated-of the 38 separate sightings only one was recovered in tissue culture. The value of the electron microscope as a rapid diagnostic tool in these cases is shown as it is often the only method of identification available.

The 1980 rubella outbreak in New Zealand.

From late 1979 to 1981 there was an outbreak of rubella in New Zealand, most parts of the country being affected. The diagnostic virus laboratory at the National Health Institute, Wellington, examined approximately 15 000 sera for rubella during this period. The total number diagnosed as positive for rubella was 186. The extent of the outbreak was seen when these numbers were compared with rates of positive cases/numbers tested in the year from 1973. Of those diagnosed as having rubella infection, 63 percent were women of child-bearing age and approximately half of these (37 percent) were in various stages of pregnancy. Also an assessment of rubella immunity in New Zealand was made, comparing results of a survey carried out in 1976-1977 with antibody levels obtained by the laboratory from sera tested in 1979 and 1980. In 1980 we found that 12 percent of women in the child-bearing age group lacked adequate immunity, notwithstanding an actively pursued national rubella immunisation programme initiated in 1970.

Sterilization of soft contact lenses using boiling water in a vacuum flask.

The vacuum flask method of using boiling water to decontaminate soft contact lenses is better and less expensive than other ways of using moist heat and can be safely and effectively applied under most domestic circumstances.