Ken Kobayashi

Foreign body reactions (FBRs) are inadvertently observed in invading or artificially embedded materials, triggering inflammation and subsequent fibrotic processes to occur in situ. Here, we assessed the spatiotemporal formation of connective tissue around implanted materials to establish a technique using connective tissue formed by FBRs as xenografts. An acrylic resin implant, comprising a columnar inner rod and a tubular outer cylinder (OC) with several slits, was embedded in adult dairy cows. Tissues formed in the inner rod and OC groups were histologically analyzed at weeks 2, 4, 8, and 12. Edematous tissues with non-collagenous fibers formed for 2 weeks and showed increased cellularity after 4 weeks. The weight, thickness, amounts of total protein, collagen, DNA, and quantitative scores of α-smooth muscle actin-positive myofibroblasts or elastic fibers notably increased after 8 weeks, with condensed collagen fibers showing orientation. Inflammatory cells were primarily localized in tissues close to the OC, and their numbers increased, with the count of CD204+ cells peaking at 8 weeks and declining at 12 weeks. The count of Ki67+ proliferating cells slightly increased in tissues close to the OC; however, the number and lumen of CD31+ vessels increased. These results may help understand FBR-related tissue remodeling.

Dairy cows feed on isoflavones as physiologically active substances present in legumes. However, the influences of isoflavones (biochanin A, genistein, formononetin, and daidzein) and their metabolites (p‐ethylphenol and equol) on milk components production, tight junctions (TJs), and their regulatory pathways are unclear in bovine mammary epithelial cells (BMECs). In this study, we investigated the influences of isoflavones and their metabolites in BMECs using an in vitro culture model. The influences of isoflavones on milk components production, TJ proteins, and STAT5/STAT3 signaling pathways were different in a type‐specific manner. Biochanin A decreased the mRNA expression and secretion of both β‐casein and lactoferrin while a decrease in activated STAT5 and an increase in activated STAT3. In contrast, equol increased claudin‐3, which is the main components for less‐permeable TJs in lactation, while an increase in activated STAT5. In addition, a mixture of multiple isoflavones based on the intake of red clover increased secretion of lactoferrin, mRNA expression of β‐casein, and amount of claudin‐3, but a mixture based on soy did not affect the BMECs. Thus, these results indicate that isoflavones in legumes and the metabolic activity of isoflavones in dairy cows when feeding legumes may affect the milk production ability in BMECs.