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Despite eradication attempts, measles remains a global health concern. Here we report results that demonstrate that a single-dose DNA immunization followed by multiple boosters, delivered orally as a plant-derived vaccine, can induce significantly greater quantities of measles virus-neutralizing antibodies than immunization with either DNA or plant-derived vaccines alone. This represents the first demonstration of an enhanced immune response to a prime-boost vaccination strategy combining a DNA vaccine with edible plant technology.

In the recent past, total hip replacement (THR) surgery in naval aviation personnel has been considered for selected individuals. There is a trend in the armed services to return individuals to flight status after total hip arthroplasty. Some individuals have successfully returned to ejection seat aircraft. A case report of an aviator who returned to tactical flying in the F/A-18 community is presented. This naval aviator has functioned successfully on a shipboard environment and accumulated in excess of 900 flight hours without functional compromise after successful hip arthroplasty, reporting no difficulty with aviation-related ergonomic issues, such as ingress/egress, sitting in a confined cockpit, or tolerating G forces. Two other individuals have also returned to flight status, but have not accumulated a significant number of flight hours to warrant evaluation. Irrespective of the apparent early success in returning to flight status, significant concerns remain. This preliminary assessment of individuals returned to flight status after THR appears to justify return to flight status, including ejection seat aircraft. However, there is a potential for hip fracture or dislocation in the event of ejection or PLF which poses significant risks for aircrews requesting return to flight status after THR. Additionally, personnel in this relatively young population should be advised of the likelihood of accelerated wear imposed by strenuous activity.

The cultivation of plants with specific properties has been the foundation of medicine for milennia. Modern biotechnology may one day extend their medicinal uses to include the delivery of vaccines. Edible vaccines that are heat stable, easy to administer and cheap to produce have the potential to redress many of the production, distribution and delivery limitations faced by traditional vaccines. Published data have shown that the concept of an edible vaccine is valid. Transition from a model system into a practical reality still has some way to go, including managing issues of oral tolerance, genetically modified organism safety, and effective vaccine doses. Successful edible vaccines have the potential to transform health policy and practice in both developed and developing countries.

Sequences from the coat protein cistron of five ryegrass mosaic virus (RgMV) isolates indicated the presence of two distinct strains in New Zealand. The nucleotide differences between the strains, and their distribution, suggested that both strains were introduced recently, either as a mixed infection or as two independent introductions. The relationship between these New Zealand strains and other strains and isolates of RgMV, and their potential severity is discussed.

The sequences of the 3'-terminal 1.8 kb of the genomes of three Australian and three Welsh isolates of ryegrass mosaic rymovirus (RGMV) were determined, as too were the virion protein genes of two New Zealand isolates of RGMV. They were compared with each other and with the published sequences of a Danish and a South African isolate by distance and maximum likelihood methods, and found to be very closely related (mean nucleotide difference 5.5%). All three Australian isolates and one from North Island of New Zealand formed one consistent cluster, and the Danish and South African isolates formed another. However the relationships between these two clusters and the other isolates were not consistent; they depended on the method of comparison used, and on the protein, gene or codon position compared. Nonetheless the European (Welsh and Danish) sequences were 2-4 times more different from one another than those from the Antipodes, suggesting that the European RGMV population may be older than the Antipodean. The Danish isolate has 39 nucleotides of the 5'-terminal region of its virion protein gene frameshifted -1 relative to the 'common' sequence. Interestingly the South African isolate has a similar frameshift, but sequence comparisons indicate that this frameshift must have occurred independently; a possible example of 'convergent frameshifting'.

Thirty infants scheduled for a variety of gastrointestinal, genitourinary and thoracic surgical procedures were selected for insertion of lumbar or thoracic epidural catheters via the caudal approach using either an Intracath or a Burron continuous brachial plexus kit. The catheters were inserted with ease by residents in training and no catheter-related complications were encountered. Lidocaine 0.5 per cent with 1:200,000 epinephrine was then injected to assure proper placement of the catheter before narcotics were administered. Postoperative analgesia was adequate in all patients using preservative-free morphine 0.05 mg.kg-1. The mean dosing interval was 15 hr and no episodes of nausea, vomiting, hypotension or histamine release were noted. Urinary retention occurred in two infants and one infant became apnoeic three hours after epidural morphine administration but responded to naloxone and pulmonary ventilation with bag and mask. In conclusion, epidural catheters placed via the caudal approach are a safe and effective means of providing postoperative pain control in infants using preservative-free morphine. However, the use of epidural narcotics in infants less than two years of age is restricted to those who will receive intensive care unit monitoring postoperatively so that if apnoea occurs, rapid intervention can be taken by skilled nursing personnel.

Prolonged papain digestion of rat IgG2a has recently been shown to yield two species of Fc fragments, termed Fc(I) AND Fc(II). The results of structural studies indicated that Fc(II) fragment was 15 to 20% smaller than Fc(I), probably secondary to loss of a carboxy-terminal peptide. The effects of these structural laterations on the catabolism and biologic properties of the Fc fragments were determined. The results of catabolic experiments indicated that after injection into normal rats Fc(I) fragments were retained in the circulation and slowly catabolized whereas Fc(II) fragments rapidly underwent filtration in the kidneys. In nephrectomized rats, however, both Fc(I) and Fc(II) fragments possessed identical slow rates of catabolism, as determined by serum disappearance and whole body catabolic experiments. Fragment pFc, corresponding to Cgamma3 domain, was different from either of the Fc fragments in exhibiting rapid rates of catabolism in both normal and nephrectomized rats. Fc(I) was more active in complement fixation and in adherence to the Fc receptor on monocytes in comparison with Fc(II). These results support the conclusion that catabolism of Fc and maintenance in circulation are separate processes influenced by different structures in the Fc fragment. The catabolism of Fc is controlled by structures in the Cgamma2 domain. This process probably is not related either to complement fixation or to adherence to the Fc receptor on monocytes. Some correlations between the structure and biologic properties of these Fc fragments are discussed.

Mastitis in its complexity has managed to forestall all efforts of eradication in spite of years of research, antibiotics and practical control measures. This minisymposium will touch on seven topics current to treatment and control of this economically important disease.

Two polygalactolipids, designated as components A and B, were isolated from spinach chloroplasts and were also obtained from glycolipid products synthesized with chloroplast enzymes using uridine diphosphate galactose as a galactose donor. These lipids were purified by column and thin layer chromatography. Chemical analysis of component A indicates that the lipid is trigalactosyl diglyceride, whereas component B behaves like tetragalactosyl diglyceride on a thin layer plate. The major fatty acid in trigalactosyl diglyceride was alpha-linolenic acid. Relative amount (molar ratio) of galactolipids in spinach chloroplasts was monogalactosyl diglyceride:digalactosyl diglyceride:trigalactosyl diglyceride:(tetragalactosyl diglyceride) = 60:30:5:1.