Negative Pregnancy Test in Patients with Trophoblastic Diseases

The role of legal medicine professionals in preventing pregnancy and sexually transmitted infections among female victims of sexual assault

Sexual violence can have an overwhelming impact on the victim's physical and mental health; the consequences include unintended pregnancy and sexually transmitted infections (STIs). Therefore, the examiners must assess victims for possible pregnancy and sexually transmitted infections as a part of the sexual assault examination. This article aims to orient the medico-legal examiners towards their role in preventing unintended pregnancy and sexually transmitted infections among victims of sexual assault. Prompt detection of pregnancy or STIs is critical, as any delay would adversely affect the successful administration of emergency contraception and post-exposure prophylaxis (PEP) against human immunodeficiency virus (HIV) and other sexually transmitted infections.

Mitigating hook effect in one-step quantitative sandwich lateral flow assay by timed conjugate release

Sandwich lateral flow assay (LFA) is one of the most successfully commercialized paper-based biosensors, which offers a rapid, low-cost, one-step assay. Despite its advantages, conventional sandwich LFA is fundamentally limited by the high-dose "hook" effect-a phenomenon that occurs at very high analyte concentrations and results in false-negative results. In this paper, we present a novel strategy of automatic timed detection antibody release to mitigate the hook effect in sandwich LFA without additional manual steps. We introduced an intermediate pad treated with saturated sucrose solution to regulate the flow between the nitrocellulose membrane and the conjugate pad in order to delay the reaction between detection antibodies and analytes. Using C-reactive protein (CRP) as a representative analyte, we demonstrated that our strategy exhibited a range of detection 10 times wider than that of our conventional LFA, without sacrificing the limit of detection. Comparing to other published strategies, our work could offer a one-step, cost-effective approach that is closely unified with the benefits of the LFA.

Perimenopausal giant hydatidiform mole complicated with preeclampsia and hyperthyroidism: A case report and literature review

Gestational trophoblastic disease (GTD) commonly occurs in reproductive females, but is extremely rare in perimenopausal females. In this study, we reported a case of hydatidiform mole in a 48-year-old perimenopausal female admitted due to a giant uterine mass of 28 weeks' gestational size. The serum human chorionic gonadotropin (HCG) level ranged from 944 to 1,286 mIU/mL before treatments. The signs of preeclampsia and hyperthyroidism were relatively prominent. Hysterectomy was performed and chemotherapy was scheduled when the serum HCG level remained at a plateau, about 528 mIU/mL. The symptoms of preeclampsia and hyperthyroidism were relieved after treatment. Accordingly, we concluded that GTD could occur in perimenopausal woman and hysterectomy usually is the optimal treatment.

The "hook effect" causing a negative pregnancy test in a patient with an advanced molar pregnancy

•At high hCG levels in molar pregnancies, a "hook effect" can cause an artificially negative value.•Delay in diagnosis of a molar pregnancy due to the "hook effect" can lead to severe complications.•Suspicion of a molar pregnancy should be communicated so a diluted sample is used to quantify hCG.