Patient case (clinical description): A 32-year-old woman comes to the hospital with vaginal spotting.  Her last menstrual period was 10 weeks ago. She has regular menses lasting for 6 days and repeating every 29 days. Medical history is significant for appendectomy and several complicated UTIs. She has multiple male partners, and she is inconsistent with using barrier contraceptives. Vital signs are normal.  Serum β-hCG level is 1800 mIU/mL, and a repeat level after 2 days shows an abnormal rise to 2100 mIU/mL.  Pelvic ultrasound reveals a thin endometrium with no gestational sac in the uterus.

Patient's own account: I just turned 32 and last morning I woke up with strange blood stains on my underwear. My last periods were more than 2 months ago, which is unusual for me because I used to have regular periods lasting for 6 days every 29 days, more or less. I had several UTIs in the past. I also had appendicitis. I'm currently seeing several men and, to be honest, some of them do struggle to wear a condom. I went to the hospital to check myself up and they told me that my vitals were normal. I also had a blood test on Monday, and my β-hCG level was 1800 mIU/mL, and then on Wednesday, it went up to 2100 mIU/mL. The gynecologist also did an ultrasound and she told me that, hopefully, there was no ovule.

Clinical trial: Exploratory Pharmacodynamic Study of Tenofovir-Based Products

Eligibility criteria:
Inclusion Criteria:

          -  General good health (by volunteer history and per investigator judgment) without any
             clinically significant systemic disease (including, but not limited to significant
             liver disease/hepatitis, gastrointestinal disease, kidney disease, thyroid disease,
             osteoporosis or bone disease, and diabetes) and with an intact gastrointestinal tract,
             uterus and cervix

          -  Currently have regular menstrual cycles of 21-35 days by participant record

          -  Willing to abstain from vaginal intercourse and any other vaginal activity including
             use of vaginal products (tampons, spermicides, lubricants, and douches) other than
             study products:

               -  48 hours before Visit 2 until six days after Visit 2

               -  48 hours before Visit 3 until six days after Visit 4

          -  Vaginal and cervical anatomy that, in the opinion of the investigator, lends itself to
             easy genital tract sample collection

          -  Estimated calculated creatinine clearance (eCcr) of at least 60 mL/min

          -  History of Pap smears and follow-up consistent with standard clinical practice as
             outlined in the study manual or willing to undergo a Pap smear at Visit 1

          -  Protected from pregnancy by one of the following:

               -  sterilization of either partner

               -  abstinence

               -  same sex relationship

               -  condoms

               -  combined contraceptives (including oral, patch)

               -  copper IUD

          -  Willing and able to comply with protocol requirements including swallowing tablets

          -  Willing to give voluntary consent and sign an informed consent form

        Exclusion Criteria:

          -  History of hysterectomy

          -  Currently pregnant or within two calendar months from the last pregnancy outcome.
             Note: if recently pregnant must have had at least two spontaneous menses since
             pregnancy outcome

          -  Injection of Depo-Provera in the last 10 months or use of other progestin-only based
             contraceptive (including hormonal IUD)

          -  Currently breastfeeding or planning to breastfeed during the course of the study

          -  History of sensitivity/allergy to any component of the study products, topical
             anesthetic, or to both silver nitrate and Monsel's solution

          -  In the last three months, diagnosed with or treated for any STI, by self report

          -  Positive test for Trichomonas vaginalis, Neisseria gonorrhea, Chlamydia trachomatis,
             HIV, or Hepatitis B surface antigen (HBsAg) Note: Women with a history of genital
             herpes who have been asymptomatic for at least three months may be considered for
             eligibility

          -  Chronic or acute vulvar or vaginal symptoms (pain, irritation, spotting/bleeding,
             discharge, etc.)

          -  Known bleeding disorder that could lead to prolonged or continuous bleeding with
             biopsy

          -  Systemic use in the last two weeks or anticipated use during the study of any of the
             following: corticosteroids, antibiotics, anticoagulants or other drugs known to
             prolong bleeding and/or clotting, antifungals, or antivirals (e.g., acyclovir,
             valacyclovir, Viread®, Atripla®, Emtriva®, or Complera®)

          -  Current or anticipated chronic use of NSAIDS, or Tylenol for the duration of the study

          -  Grade 2 or higher laboratory abnormality, per the 2014 update of the Division of AIDS,
             National Institute of Allergy and Infectious Disease (DAIDS) Table for Grading the
             Severity of Adverse Events, or clinically significant laboratory abnormality as
             determined by the clinician

          -  Abnormal finding on laboratory or physical examination or a social or medical
             condition in either the volunteer or which, in the opinion of the investigator, would
             make participation in the study unsafe or would complicate interpretation of data

          -  Known current drug or alcohol abuse which could impact study compliance

          -  Participation in any other investigational trial within the last 30 days or planned
             participation in any other investigational trial during the study

          -  History of gynecological procedures (including genital piercing) on the external
             genitalia, vagina or cervix within the last 14 days
Female
Accepts Healthy Volunteers
Subject must be at least 18 Years old.
Subject must be at most 50 Years

Eligibility (NLI label): Contradiction