To describe and discuss the morphology of the aged thyroid gland, with particular reference to the contribution of macrophages.With the aid of immunohistochemistry, we examined 1) macrophage accumulation, 2) infiltration of lymphocytes, and 3) the size and density of follicles in the unilateral lobe of the thyroid gland obtained from elderly donated cadavers (mean age, 84 years) without macroscopic malignancy. Each almost entire unilateral lobe of the thyroid showed 2554-9910 follicles per section, and each of the follicles ranged in area from 0.014-0.072 mm2. We often found evidence suggesting absorption and fusion of follicles to provide a larger colloidal lumen, containing small follicles and/or epithelial fragments. In addition to dendritic perifollicular macrophages, large and round macrophages often formed clusters in the colloid. Colloidal lumina with weak macrophage immunoreactivity were intermingled with those showing strong reactivity. Notably, a greater number of macrophage foci in the colloid was usually associated with a lower density of perifollicular macrophages. Likewise, perifollicular macrophages were not always associated with lymphocyte infiltration. In the elderly, the initial appearance of colloidal macrophages does not appear to be associated with perifollicular infiltration of mononuclear cells. Macrophage invasion into a follicle might depend on the functional state of each follicle. After destruction of a follicle, a macrophage cluster appears to remain in the perifollicular tissue, and perhaps lymphocyte infiltration occurs secondarily. This course is likely to represent the process of degeneration of the thyroid gland structure with age.
Recently, health awareness in Japan has been increasing and active exercise is now recommended to prevent lifestyle-related diseases. Cytokine activities have many positive effects in maintaining the health of a number of organs in the body. Myokines are cytokines secreted by skeletal muscles in response to exercise stimulation, and have recently generated much attention. Around 700,000 patients in Japan suffer from rheumatoid arthritis, making it the most prevalent autoimmune disease that requires active prevention and treatment. In the present study, a mouse model of spontaneous arthritis (SKG/Jcl) was subjected to continuous exercise stimulation, starting before the disease onset, to examine the effects of anti-inflammatory and inflammatory cytokine secretion on arthritis. For this stimulation, we developed a device that combines shaking and vibration. The results revealed that exercise stimulation delayed the onset of arthritis and slowed its progression. Thickened articular cartilage and multiple aggregates of chondrocytes were also observed. Further, exercise stimulation increased the expression of IL-6, IL-10, and IL-15, and inhibited TNF-α expression. From these results, we infer that the anti-inflammatory effects of IL-6 and IL-10, which showed increased expression upon exercise stimulation, inhibited the inflammatory activity of TNF-α and possibly delayed the onset of arthritis and slowed its progression. Novel methods for preventing and treating arthritis under clinical settings can be developed on the basis of these findings.
The purpose of this study was to explore the crown shapes of maxillary molars with delayed eruption (DEMo1) at the position distal to the maxillary second premolar. Included teeth erupted later than the average for the maxillary first molar eruption in Japanese females (6.58 ± 0.67 years) by more than two standard deviations. Crown shapes of 12 four-cusped left DEMo1 teeth were compared with those of 25 four-cusped left maxillary first molars (U6n) and 25 four-cusped left maxillary second molars (U7n) from different patients with normal eruption. Seven landmarks were established on the reference plane containing the mesiobuccal, distobuccal and mesiolingual cusp tips of the molars; the origin was defined as the center of gravity of these three points. According to the obtained discriminant function (percentage of correct classifications, 84%), five DEMo1 teeth were classified as U6n and the other seven as U7n. The DEMo1 teeth were also classified into two subgroups, the U6n-close and U7n-close groups, according to the location of the distolingual cusp tip. These results suggest that DEMo1 teeth could include U6 and U7 with delayed eruption or could be an intermediate between U6 and U7, according to their crown shapes.
We examined the dorsal lingual surfaces of an adult eland (Taurotragus oryx) by scanning electron microscopy. Filiform, fungiform and vallate papillae were observed. The filiform papillae of the lingual apex consisted of a larger main papilla and smaller secondary papillae. The connective tissue core of the filiform papilla was U-shaped. The fungiform papillae were round in shape. The connective tissue core of the fungiform papilla was flower-bud shaped. The filiform papillae of the lingual body consisted of a main papilla and were big as compared to that of the lingual apex. The connective tissue core of the filiform papilla resembled that of the lingual apes. The lenticular papillae of large size were limited on the lingual prominence. The connective tissue core of the lenticular papilla consisted of numerous small spines. The vallate papillae were located on both sides of the posterolateral aspects. The vallate papillae were flattened-oval shaped and the papillae were surrounded by a semicircular trench. The connective tissue core of the vallate papilla was covered with numerous small spines. The lingual surface of the eland closely resembled that of the family Bovidae.
We examined the dorsal lingual surface of an adult Asian short-clawed otter (Aonyx cinerea) by using scanning electron microscopy. The filiform papilla on the lingual apex had some pointed processes. The connective tissue core of the filiform papillae consisted of several rod-like processes, and the connective tissue core with a long process was rarely observed. The filiform papilla on the lingual body had several pointed processes and the fungiform papilla had smooth surface. The connective tissue core of the filiform papillae consisted of a large main and several small processes. The vallate papillae were surrounded by a groove and some pads, and many processes were observed on this surface. The tongue of the Asian short-clawed otter was different from that of the Japanese marten belong to family Mustelidae.