Recent studies have suggested an association of genetic and neurodevelopmental factors with development of paraphilia. In this case report on monozygotic twins with pedophilia, we aim to offer additional evidence indicating that genetic vulnerability may be a significant risk factor along with environmental influences on development of pedophilia. These twin pairs, who have been arrested for sexual offenses against boys, had experienced emotional and physical abuse during their childhood, and the older twin brother is reported to have a history of sexual abuse. Both showed homosexual tendencies, and the younger twin brother was also diagnosed as exhibitionism. This case implies greater involvement of genetic factors and associated vulnerabilities in the etiology of paraphilia, including pedophilia, than environmental factors such as childhood abuse. In the future, conduct of research will be needed in order to determine the biological markers related to the etiology of pedophilia.
Biomarkers ; Exhibitionism ; Homosexuality ; Humans ; Paraphilic Disorders ; Pedophilia* ; Risk Factors ; Sex Offenses ; Siblings ; Twins, Monozygotic*

Background: Hematopoietic stem/progenitor cells (HSPCs) have the property to return to the bone marrow, which is believed to be critical in situations such as HSPC transplantation. This property plays an important role in the stemness, viability, and proliferation of HSPCs, also. However, most in vitro models so far have not sufficiently simulated the complicate environment. Here, we proposed a three-dimensional experimental platform for the quantitative study of the migration of HSPCs. Methods: After encapsulating osteoblasts (OBs) in alginate beads, we quantified the migration of HSPCs into the beads due to the physical environment using digital image processing. Intermittent hydrostatic pressure (IHP) was used to mimic the mechanical environment of human bone marrow without using any biochemical factors. The expression of stromal cell-derived factor 1 (SDF-1) under IHP was measured. Results: The results showed that the presence of OBs in the hydrogel scaffold initiate the movement of HSPCs. Furthermore, the IHP promotes the migration of HSPCs, even without the addition of any biochemical factors, and the results were confirmed by measuring SDF-1 levels. Conclusion We believe this suggested three-dimensional experimental platform consisting of a simulated in vivo physical environment and encapsulated OBs should contribute to in vitro migration studies used to investigate the effects of other external factors.

Background: Hematopoietic stem/progenitor cells (HSPCs) have the property to return to the bone marrow, which is believed to be critical in situations such as HSPC transplantation. This property plays an important role in the stemness, viability, and proliferation of HSPCs, also. However, most in vitro models so far have not sufficiently simulated the complicate environment. Here, we proposed a three-dimensional experimental platform for the quantitative study of the migration of HSPCs. Methods: After encapsulating osteoblasts (OBs) in alginate beads, we quantified the migration of HSPCs into the beads due to the physical environment using digital image processing. Intermittent hydrostatic pressure (IHP) was used to mimic the mechanical environment of human bone marrow without using any biochemical factors. The expression of stromal cell-derived factor 1 (SDF-1) under IHP was measured. Results: The results showed that the presence of OBs in the hydrogel scaffold initiate the movement of HSPCs. Furthermore, the IHP promotes the migration of HSPCs, even without the addition of any biochemical factors, and the results were confirmed by measuring SDF-1 levels. Conclusion We believe this suggested three-dimensional experimental platform consisting of a simulated in vivo physical environment and encapsulated OBs should contribute to in vitro migration studies used to investigate the effects of other external factors.