The CCL2-2518G allele increases the risk of developing TB in Asians and Hispanics.

Mono-ortho and non-ortho coplanar polychlorinated biphenyls (PCBs) were analyzed in Aroclors, seals, and humans by graphitized carbon, a recently developed HPLC method (Hong et al. 1992b) and high-resolution gas chromatography with electron capture detection (HRGC/ECD). The concentration data were multiplied by potency factors derived from aryl hydrocarbon hydroxylase (AHH) induction to give 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) equivalents. The ability to separate coplanar PCBs from the majority of PCBs has allowed the use of TCDD toxicity equivalence to compare the relative dioxin-like potency of PCB residues in the complex mixtures. The most active mixtures, Aroclors 1254, 1248, and 1242, contained 42-54% by weight of chlorine. The results demonstrate that the apparent dioxin-like potency of PCB residues in Aroclors, seals, and humans is dominated by three congeners, 3,3',4,4'-tetra-, 2,3,3'-4,4'-, and 3,3',4,4',5-pentachlorobiphenyl (IUPAC nos. 77, 105, 126).

Background Spermatogenesis is an intricate developmental process during which undifferentiated spermatogonia, containing spermatogonial stem cells (SSCs), undergo self-renewal and differentiation to generate eventually mature spermatozoa. Spermatogenesis occurs in seminiferous tubules within the testis, and the seminiferous tubules harbor Sertoli and germ cells. Sertoli cells are an essential somatic cell type within the microenvironment that support and steer male germ cell development, whereas spermatogonia are the primitive male germ cells at the onset of spermatogenesis. While the developmental progression of Sertoli cells and spermatogonia has been well established in mice, much less is known in other mammalian species including pigs. Results To acquire knowledge of Sertoli cell and spermatogonial development in pigs, here we collected as many as nine ages of Duroc porcine testes from the neonate to sexual maturity, i.e., testes from 7-, 30-, 50-, 70-, 90-, 110-, 130-, 150- and 210-day-old boars, and performed histological and immunohistochemical analyses on testis sections. We first examined the development of spermatogenic cells and seminiferous tubules in porcine testes. Then, by immunofluorescence staining for marker proteins (AMH, SOX9, DBA, UCHL1, VASA, KIT, Ki67 and/or PCNA), we delved into the proliferative activity and development of Sertoli cells and of spermatogonial subtypes (pro-, undifferentiated and differentiating spermatogonia). Besides, by immunostaining for β-catenin and ZO-1, we studied the establishment of the blood-testis barrier in porcine testes. Conclusions In this longitudinal study, we have systematically investigated the elaborate Sertoli cell and spermatogonial developmental patterns in pigs from the neonate to sexual maturity that have so far remained largely unknown. The findings not only extend the knowledge about spermatogenesis and testicular development in pigs, but also lay the theoretical groundwork for porcine breeding and rearing.