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Biomedical subjects

F Judson

Publications and source records attributed to F Judson.

7 recordsLinked to original sources

Safety and immunogenicity of a canarypox-vectored human immunodeficiency virus Type 1 vaccine with or without gp120: a phase 2 study in higher- and lower-risk volunteers.

Live attenuated viral vectors that express human immunodeficiency virus (HIV) antigens are being developed as potential vaccines to prevent HIV infection. The first phase 2 trial with a canarypox vector (vCP205, which expresses gp120, p55, and protease) was conducted in 435 volunteers with and without gp120 boosting, to expand the safety database and to compare the immunogenicity of the vector in volunteers who were at higher risk with that in volunteers at lower risk for HIV infection. Neutralizing antibodies to the MN strain were stimulated in 94% of volunteers given vCP205 plus gp120 and in 56% of volunteers given vCP205 alone. CD8(+) cytotoxic T lymphocyte cells developed at some time point in 33% of volunteers given vCP205, with or without gp120. Phase 3 field trials with these or similar vaccines are needed, to determine whether efficacy in preventing HIV infection or in slowing disease progression among vaccinees who become infected is associated with the level and types of immune responses that were induced by the vaccines in this study.

AIDS Vaccines↗

Per-contact risk of human immunodeficiency virus transmission between male sexual partners.

The risk of human immunodeficiency virus (HIV) transmission from various types of homosexual contact, including oral sex, is of biologic, epidemiologic, and public health importance. The per-contact risk of acquiring HIV infection from specific acts was estimated in a prospective cohort study of 2,189 high-risk homosexual and bisexual men, conducted in San Francisco, California; Denver, Colorado; and Chicago, Illinois, in 1992-1994. During 2,633 person-years of follow-up, 60 seroconversions were observed. The estimated per-contact risk of acquiring HIV from unprotected receptive anal intercourse (URA) was 0.82 percent (95% confidence interval: 0.24, 2.76 percent) when the partner was known to be HIV+ and 0.27 percent (95% confidence interval: 0.06, 0.49 percent) when partners of unknown serostatus were included. There was heterogeneity in per-contact risk, with nine seroconversions occurring after only one or two episodes of URA. The per-contact risk associated with unprotected insertive anal and receptive oral sex with HIV-positive or unknown serostatus partners was 0.06 and 0.04 percent, respectively. URA accounted for only 15 percent of all reported sexual activity by seroconverters. As lower-risk practices become more common, they may play a larger role in propagating the epidemic and should also be addressed by interventions targeting high-risk homosexual and bisexual men.

Cohort Studies↗

A factorial survey study to assess the acceptability of HIV vaccine trial designs.

To aid in the design of human immunodeficiency virus (HIV) vaccine trials that maximize volunteer participation, factorial surveys were administered to 73 gay men who were participants in a larger study assessing HIV vaccine trial feasibility. Factorial surveys are "vignettes" that are randomly constructed through the combination of descriptive statements (dimensions) that reflect essential features. In this study, the dimensions define components of clinical trials to assess the efficacy of hypothetical HIV vaccines. Regression analysis shows that anticipated participation was decreased by a sustained vaccine-induced antibody response lasting 3 years, absence of gay men as research subjects in earlier phase trials for the products being tested, and rectal vaccine administration. Three years of scientific experience with the vaccine encouraged participation. We conclude that willingness to participate in vaccine trials varies systematically with some of their characteristics. Where there are design alternatives for identified negative components, these should be considered. If this is not possible, options for decreasing aversion to such features will need to be evaluated, including appropriate education regarding both the benefits and the risks associated with negatively evaluated features.

AIDS Vaccines↗

Adsorption of botulinum toxin to activated charcoal with a mouse bioassay.

STUDY OBJECTIVE: We evaluated the effectiveness of activated charcoal (AC) in adsorbing Clostridium botulinum type A toxin using a mouse bioassay. DESIGN: Prospective, blinded, randomized, controlled animal study. SETTING: Animal care facility. PARTICIPANTS: One hundred forty Swiss/Webster ND-4 strain mice. INTERVENTION: Food contaminated with type A botulinum toxin was homogenized in a phosphate/gel buffer (pH 6.2). The concentrate was diluted by factors of 1:10, 1:50, and 1:100. AC was added to aliquots of the dilutions to a 20% final concentration. The samples were centrifuged, supernatant was removed, and separate groups of mice were injected intraperitoneally with .5 mL of each dilution (those treated with AC and controls untreated with AC). The animals were then observed over 5 days for signs of botulism. RESULTS: None of the 60 animals injected intraperitoneally with dilutions treated with AC was observed to have any signs of botulism. In contrast, deaths were observed in 10 of 20, 9 of 20 and 4 of 20 mice injected with untreated dilutions of 1:100, 1:50, and 1:10, respectively (P < .004). CONCLUSION: In this model, treatment of botulinum toxin with AC before administration resulted in greatly reduced morbidity and mortality.

Adsorption↗

Preparations for AIDS vaccine trials. Developing brief valid screening instruments for HIV-related sexual risk behavior among gay and bisexual men.

Enrolling and tracking cohorts for HIV vaccine efficacy trials requires that participants disclose behaviors that place them at risk for exposure to HIV. Brief screening procedures have been suggested for this purpose. In a previous study gay and bisexual men in three U.S. cities reported unprotected anal intercourse on a brief screening instrument. Screen reports were compared to subsequent in-depth, face-to-face interview data; 29% of the men who reported unprotected anal intercourse during the interview failed to disclose this behavior during screening. For recruitment into an HIV vaccine feasibility study at the same study sites, screening procedures were modified to encourage accurate reporting: to lessen stigma, low risk as well as high risk sexual behaviors were assessed, and screens were administered by trained study staff who presented it as a tool for understanding the gay community. Failures to disclose risk decreased to 18%, a rate that, while lower than in the previous study, remains high. Men less likely to disclose unprotected sex during the screen engaged in fewer high risk sexual behaviors, had more stringent norms regarding sexual safety, and were less identified with the gay community than were men who disclosed unprotected sex. Failure to disclose risk may have significant implications for participant selection and behavior tracking during vaccine trials. More systematic assessments that are sensitive to target communities may facilitate disclosure.

AIDS Vaccines↗

Interferon therapy for condylomata acuminata.

Current therapy for condylomata acuminata (genital warts) is not consistently effective. Therefore, we conducted a randomized, double-blind trial to compare interferon alpha-2b with placebo in the treatment of this disorder. Our rationale was that interferon has both antiproliferative and antiviral properties. The placebo or interferon (1 X 10(6) IU) was injected directly into one to three warts three times weekly for three weeks. The injections were well tolerated by both groups of patients. The side effects of fever, chills, myalgia, headache, fatigue, and leukopenia occurred more commonly in the interferon group than in the placebo group, but such effects rarely disrupted daily routines. Only 13 of 296 patients (4 percent) discontinued therapy because of side effects (11 in the interferon group and 2 in the placebo group). Twenty-six other patients were excluded from analysis because of a loss to follow-up or other deviations from protocol, thus leaving 257 patients in the final evaluation. At one week after the completion of therapy, interferon had produced a large and significantly greater reduction in mean wart area (a 62.4 percent decrease), as compared with placebo (a 1.2 percent increase in mean area) (P less than 0.001). At the conclusion of the study (13 weeks after the completion of therapy), the mean wart area was still decreased 39.9 percent below the initial size in the interferon group, whereas it had increased by 46 percent over base-line measurements in the placebo group (P less than 0.001). At the same time, all treated warts had completely cleared in 36 percent of the interferon recipients and in 17 percent of the placebo recipients (P less than 0.001), whereas treated warts progressed in 13 percent of the interferon recipients and in 50 percent of the placebo recipients (P less than 0.001). We conclude that injection of interferon alpha-2b directly into genital warts appears to be an effective and fairly well-tolerated form of therapy.

Adolescent↗

The establishment of a venereal disease clinic: II. An appraisal of current diagnostic methods in uncomplicated urogenital and rectal gonorrhea.

Some of the diagnostic procedures for uncomplicated urogenital and rectal gonorrhea were studied in a university-based venereal disease clinic. On the basic of our results, recommendations are made concerning the types of media to be used, sites to be sampled, methods of obtaining specimens, and other diagnostic considerations. We conclude that ongoing quality control including a review of diagnostic procedures should be carried on in all venereal disease clinics.

Bacteriological Techniques↗