Effect of Seminal Fluid on the Colon Wall; Implications for HIV Transmission

Not Applicable

Completed

Interventions: Biological: Radiolabeled autologous seminal fluid
Biological: Radiolabeled Normosol-R

Brief Summary: This research is being done to learn how seminal fluid affects the lining of the colon, and whether this might make it easier for HIV to get into the body and cause infection.

Detailed Description: Design of effective rectal microbicides to prevent HIV infection requires an understanding of rectal HIV transmission and the location within the lower gastrointestinal (GI) tract (luminal and mucosal) of HIV (cell-free and cell-associated) following exposure to infected seminal fluid. These basic details of HIV transmission have yet to be determined in human subjects, yet they are essential to select microbicide candidates if they are to be rationally designed to achieve effective concentrations at sites of HIV transmission. Rational development of a rectal microbicide also requires an understanding of those factors that may contribute to colonic mucosal injury - potential confounders of microbicidal effect. Such factors include exposure to seminal fluid which has been shown in animal and in vitro studies to cause histologic and permeability changes that might facilitate HIV transmission.

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

Active anorectal disease or recent (3 months) anorectal surgery;
Diarrhea, defined as three or more loose stools per day, for at least three days prior to admission.
History of sleep apnea, or airway problems with previous sedation procedures.
History of significant adverse reaction to sedation medications.
Other history, including significant occupational radiation exposure, history of inflammatory bowel disease or any other diseases and lab results, such that, in the judgment of the investigator, study procedures are not considered safe for the subject's participation.

Arm && Interventions

Group	Intervention	Description
Normosol then Seminal Fluid	Radiolabeled Normosol-R	2.5 mL radiolabeled Normosol-R administered rectally x1. Two week pause between interventions. Then 2.5 mL radiolabeled autologous seminal fluid administered rectally X1.
Seminal Fluid then Normosol	Radiolabeled autologous seminal fluid	2.5 mL radiolabeled autologous seminal fluid administered rectally x1. Two week pause between interventions. Then 2.5 mL radiolabeled Normosol-R administered rectally X1.
Normosol then Seminal Fluid	Radiolabeled autologous seminal fluid	2.5 mL radiolabeled Normosol-R administered rectally x1. Two week pause between interventions. Then 2.5 mL radiolabeled autologous seminal fluid administered rectally X1.
Seminal Fluid then Normosol	Radiolabeled Normosol-R	2.5 mL radiolabeled autologous seminal fluid administered rectally x1. Two week pause between interventions. Then 2.5 mL radiolabeled Normosol-R administered rectally X1.

Primary Outcome Measures

Name	Time	Method
Epithelial Disruption Graded by a Pathologist Blinded to Study Intervention.	One hour	Endoscopy will be performed to obtain biopsy specimens at baseline and following each inpatient enema exposure. Samples will be obtained at each flexible sigmoidoscopy and set aside for batch sectioning and H\&E staining. Slides will be reviewed and scored by a qualified pathologist blinded to treatment assignment using a qualitative scoring system. This scoring system uses semi-quantitative scoring that focuses on acute toxicity to epithelial cell layer similar to that seen in animal studies. This is a categorical grading scale, where 0 = Epithelial surface intact;1 = \<1/3 of surface denuded; 2 = 1/3 - 2/3rds of surface denuded;3 = More than 2/3rds of surface denuded. Six separate biopsies for each subject and each treatment intervention were analyzed in a multi-level analysis. In comparison with the baseline condition (no intervention), the odds and 95% confidence interval (CI) of having a higher epithelial denudation score were calculated for each intervention.

Secondary Outcome Measures