Biomedical subjects

C O'Neal

Publications and source records attributed to C O'Neal.

10 recordsLinked to original sources

PubMed1997

Virus-like particle vaccines for mucosal immunization.

Viruses which infect the gastrointestinal tract are well suited for examining the immune response(s) to oral delivery of antigen and exploring the advantages and pitfalls of oral vaccines. We have used recombinant DNA techniques to produce nonreplicating self-assembled virus-like particles (VLPs) from two gastrointestinal viruses, rotavirus and Norwalk virus. Both of these viruses normally cause acute gastroenteritis in man or animals. The VLPs are morphologically and antigenically similar to the native virus and quite stable, features which are advantageous for their use as subunit vaccines. In addition, these VLPs could be useful as carriers of foreign epitopes from heterologous pathogens or of drugs which need to be delivered to the gastrointestinal track. This paper briefly reviews the properties of these VLPs made in insect cells and data showing their potential as subunit vaccines for parenteral or oral delivery.

Administration, Oral↗

PubMed1996

Rotavirus subunit vaccines.

We evaluated rotavirus subunit vaccines for use in humans and animals. Insect cells were co-infected with combinations of individual baculovirus recombinants expressing human, bovine or simian rotavirus VP2, VP4, VP6 or VP7 to produce virus-like particles (VLPs). To determine whether immunization with VLPs could induce active protective immunity, VLPs were administered parenterally to rabbits, and the immune response and protection from rabbit ALA rotavirus challenge were evaluated. Complete or partial protection was attained, showing that parenteral immunization with VLPs induces active protective immunity. We also examined whether heterotypic immune responses could be induced with a limited number of broadly reactive VP7 proteins or with chimeric particles (multiple VP7 types on individual particles). The feasibility of this approach was determined by immunizing mice with VLPs containing a G3 VP7 or G1 VP7 and chimeric G1/G3 VLPs. Broadly reactive neutralizing antibody was induced by the G1 VLPs. VLPs also have been successfully used to boost lactogenic (colostral and milk) immunity in dairy cows. Taken together, these results show that VLPs can be effective immunogens in rabbits, mice and dairy cattle when administered parenterally, a limited number of VLPs may be sufficient to produce a broadly protective vaccine, and G3 VLPs may serve as an effective subunit vaccine for use in bovines.

Animals↗

PubMed1993

Managed care is in your future.

Though Texas has been slower than most other large states to move into managed care, it is gaining ground. According to the Texas Health Maintenance Organization Association, 1.2 million Texans were enrolled in HMO plans in January 1990. Three years later, 1.5 million had signed on--a 24 percent increase. State enrollment in other managed care plans, which aren't required to file reports with state regulatory agencies, was estimated to be 6.9 million (41 percent of Texans) in 1991, according to Blue Cross/Blue Shield. While these state enrollment figures are large, the most recent numbers available indicate that Texas hospitals have a long way to go. A 1991 AHA survey found that 259 Texas hospitals (47 percent of those surveyed) do not have contracts with HMOs or PPOs. With changes coming at break-neck speed, how can these hospitals position themselves to survive and prosper in the managed care world? This month, HealthTexas presents three examples of hospitals and health care systems that have successfully made the transition to managed care. Their stories illustrate three very different approaches--developing a network, direct contracting, and establishing a health plan. And, those who have led these ventures offer advice to help other hospitals make the transition a little easier.

Data Collection↗

PubMed1988