Display of peptides on the surface of tobacco mosaic virus particles.

In this review, we focus on the potential that tobacco mosaic virus (TMV) has as a carrier for immunogenic epitopes, and the factors that must be considered in order to bring products based on this platform to the market. Large Scale Biology Corporation developed facile and scaleable methods for manufacture of candidate peptide display vaccines based on TMV. We describe how rational design of peptide vaccines can improve the manufacturability of particular TMV products. We also discuss downstream processing and purification of the vaccine products, with particular attention to the metrics that a product must attain in order to meet criteria for regulatory approval as injectable biologics.

Postvasectomy semen analysis: why patients don't follow-up.

Semen analysis following elective vasectomy is necessary to confirm that the procedure was successful. However, many patients fail to follow postoperative instructions to obtain semen analysis. One hundred forty-one patients who had undergone vasectomy at the Family Practice Center of the Medical College of Ohio were surveyed to assess reasons for a poor rate of follow-up after vasectomy. Only 26 percent of respondents had returned two or more semen samples following surgery. Forty-five percent had not returned any samples. The inconvenience and embarrassment of having to bring semen specimens to the laboratory were identified as factors that can affect patient adherence to instructions. Respondents who had not returned any semen specimens were more likely to answer that their spouse would not be very upset if the vasectomy failed and pregnancy resulted. Our survey results identify issues for improving patient care following vasectomy. These include patient education and postoperative protocols.

PIP: This survey of the 141 post-operative vasectomy patients at the Family Practice Center of the Medical College of Ohio resulted in suggestions for modifying postoperative patient care protocol and patient education. The concern centered on the poor response rate for post operative semen analysis, where 29% returned 1 specimen, 26% returned 2 or more samples following surgery, and 45% had not returned any samples. Patient education was repetitions with the 1st verbal instructions preoperative, the 2nd verbal instructions postoperative, and a typewritten instruction sheet postoperative; additional reinforcement was given at the 1 week followup visit. Masturbation, condom, or withdrawal were recommended method of collection. 2 sterile containers were provided and the request made for a 1st collection after 12 ejaculations and a 2nd 2 or more weeks after the first. The requirement was for 2 specimens completely sperm free. The results of the questionnaire analyzed with Pearson chi-square for nominal or ordinal data and the 2 tailed remembered all 3 methods of collection; remembering was not related to whether the specimen was returned. Of those returning specimens, 70% masturbated, 20% used condoms, and 17% withdrew. 99% knew the reason for collection. Convenience was an important factor. 68% found daytime drop off inconvenient and 77% agreed that refrigeration and a next day dropoff was better. 50% were embarrassed to bring the specimen in. 59% felt that a failure in vasectomy with pregnancy was upsetting. Those not returning specimens had wives less concerned about the failure of vasectomy. 69% had mutual agreement about the vasectomy decision. 58% did not return due to inconvenience, 38% embarrassment, 29% confidence in sterility, 17% forgot, 4% afraid of repeat surgery. Recommended protocol is for a 1st aspermic specimen or a fresh specimen that shows only few, nonmotile sperm turned in in a brown bag provided along with a separate handout on semen collection and joint signatures. Motility checks should be made monthly if sperm persist. Ambivalence about future pregnancy means reevaluation of suitability of couple for vasectomy.