Bois, Melanie

The mammalian liver's regenerative ability has led researchers to engineer animals as incubators for expansion of human hepatocytes. The expansion properties of human hepatocytes in immunodeficient mice are well known. However, little has been reported about larger animals that are more scalable and practical for clinical purposes. Therefore, we engineered immunodeficient swine to support expansion of human hepatocytes and identify barriers to their clinical application. Immunodeficient swine were engineered by knockout of the recombinase-activating gene 2 ( RAG2 ) and fumarylacetoacetate hydrolase (FAH). Immature human hepatocytes (ihHCs) were injected into fetal swine by intrauterine cell transplantation (IUCT) at day 40 of gestation. Human albumin was measured as a marker of engraftment. Cytotoxicity against ihHCs was measured in transplanted piglets and control swine. We initially detected higher levels of human albumin in cord blood of newborn FAH/ RAG2 -deficient (FR) pigs compared with immunocompetent controls (196.26 ng/dL vs. 39.29 ng/dL, p = 0.008), indicating successful engraftment of ihHCs after IUCT and adaptive immunity in the fetus. Although rare hepatocytes staining positive for human albumin were observed, levels of human albumin did not rise after birth, but declined, suggesting rejection of xenografted ihHCs. Cytotoxicity against ihHCs increased after birth by 3.8% (95% CI: [2.1%–5.4%], p < 0.001) and inversely correlated with declining levels of human albumin ( p = 2.1 × 10 −5 , R 2 = 0.17). Circulating numbers of T cells and B cells were negligible in FR pigs. However, circulating natural killer (NK) cells exerted cytotoxicity against ihHCs. NK cell activity was lower in immunodeficient piglets after IUCT than in naive controls (30.4% vs. 40.1%, p = 0.011, 95% CI for difference [2.7%–16.7%]). In conclusion, ihHCs were successfully engrafted in FR swine after IUCT. NK cells were a significant barrier to expansion of hepatocytes. New approaches are needed to overcome this hurdle and allow large-scale expansion of human hepatocytes in immunodeficient swine. Impact statement There is currently a need for robust expansion of human hepatocytes. We describe an immunodeficient swine model into which we engrafted immature human hepatocytes (ihHCs). We identified the mechanism of the eventual graft rejection by the intact NK cell population, which has not been previously shown to have a significant role in xenograft rejection. By both improving engraftment and reducing NK cell-mediated cytotoxicity toward the graft through intrauterine cell transfer, we confirmed the presence of residual adaptive immunity in this model of immunodeficiency and the ability to induce hyposensitization in the NK cell population by taking advantage of the fetal microenvironment.

Abstract Coccidioidomycosis is an endemic fungal infection that is typically asymptomatic or associated with pulmonary disease. Extrapulmonary disease may involve the skin, bones, or central nervous system, yet endovascular infections are exceedingly rare. We report the first case, to our knowledge, of coccidioidomycosis of the native aorta in an immunocompromised host.

Evidence of prior autoerotic asphyxia is often difficult to establish due to the decedent's efforts to hide the activity from others. In this case report, we suggest that a healed fracture of the thyroid cartilage is indicative of prior autoerotic asphyxia activity. The decedent was a 45-year-old man who was found unclothed on the floor of his bedroom with a belt ligature around the neck. A second rope ligature was loosely wrapped around the decedent's wrists, scrotum, and penis. A definitive escape mechanism was not identified, but a nearby towel and barbell weight may have comprised a possible escape mechanism. There was no known history of depression or prior autoerotic activity. Autopsy was notable for the presence of a healed fracture of the right superior horn of the thyroid cartilage. Three-dimensional (3D) surface scanning and 3D printing was utilized to preserve the anatomical findings prior to histologic sampling. To our knowledge, this is the first reported use of 3D surface scanning and 3D printing for the purpose of documenting a forensic finding prior to alteration of the anatomical specimen for histologic sampling. Acute fractures of the superior horns of the thyroid cartilage are not infrequently seen in ligature hanging. Therefore, the presence of a healed fracture in the setting of autoerotic asphyxia likely indicates prior activity. Histologic sampling of the laryngeal cartilages to detect occult healed fractures in autoerotic asphyxia may be useful. Three-dimensional scanning and printing may alleviate concerns for specimen alteration due to histology sampling.

Abstract Estrogen receptor (ER) β is highly expressed in normal breast epithelium and a putative tumor suppressor. Atypical hyperplasia substantially increases breast cancer risk, but identification of biomarkers to further improve risk stratification is needed. We evaluated ERβ expression in breast tissues from women with atypical hyperplasia and association with subsequent breast cancer risk. ERβ expression was examined by immunohistochemistry in a well-characterized 171-women cohort with atypical hyperplasia diagnosed 1967–1991. Nuclear ERβ percent and intensity was scored in the atypia and adjacent normal lobules. An ERβ sum score (percent + intensity) was calculated and grouped as low, moderate, or high. Competing risks regression was used to assess associations of ERβ expression with breast cancer risk. After 15-year median follow-up, 36 women developed breast cancer. ERβ expression was lower in atypia lobules in than normal lobules, by percent staining and intensity (both P &lt; 0.001). Higher ERβ expression in the atypia or normal lobules, evaluated by percent staining, intensity or sum score, decreased the risk of subsequent breast cancer by 2-fold (P = 0.04) and 2.5-fold (P = 0.006). High normal lobule ERβ expression conferred the strongest protective effect in premenopausal women: the 20-year cumulative incidence of breast cancer was 0% for women younger than 45 years with high versus 31% for low–moderate ERβ expression (P = 0.0008). High ERβ expression was associated with a significantly decreased risk of breast cancer in women with atypical hyperplasia. These data suggest that ERβ may be a useful biomarker for risk stratification and a novel therapeutic target for breast cancer risk reduction. Cancer Prev Res; 8(11); 1084–92. ©2015 AACR.