Dental management of unilateral multiple impacted primary teeth

Impacted primary teeth can be caused by odontogenic tumors such as odontomas, cystic diseases such as dentigerous and eruption cysts, and fibrous hyperplasia of the gingiva, while elimination of those causes reportedly results in normal eruption of primary teeth. We describe the course of a child from the age of 1 year until 4 years 10 months who had primary tooth eruption failure and was treated with dental methods. Although primary teeth expected to spontaneously erupt were followed, there were several on the left side that remained unerupted. We performed a left maxillary and mandibular gingivectomy to closely examine the cause of eruption delay and tooth germ dislocation, as well as attempt to induce eruption of the primary teeth. Based on histopathological results, the diagnosis was fibroma. Surgical procedures did not result in clear improvement of eruption failure. In order to improve masticatory function and aesthetics, the child was fixed with an artificial denture for all primary teeth not expected to erupt.     

Prevention of hair graying by factors that promote the growth and differentiation of melanocytes

Epidermal melanocyte precursors migrate into developing hair follicles to form the melanocyte stem cell system required to supply pigmented melanocytes necessary for hair pigmentation in repetitive hair cycles. Hair graying is caused by irreversible defects in the self‐renewal and/or development of follicular melanocyte stem cells in the hair follicles. To investigate the mechanism(s) of hair graying during the normal aging process, we established a hair graying model in mice by repeatedly plucking or shaving trunk hairs. We repeatedly plucked or shaved trunk hairs to induce and accelerate the hair graying and counted the gray hairs. By using this functional model of hair graying in mice, we assessed the effects of genes known to affect melanocyte development, such as Kitl, hepatocyte growth factor (HGF) and endotheline 3 (ET3). After increasing the total numbers of cumulative hair cycles by plucking or shaving, we observed a significant increase in the gray hair of C57BL/6 mice. Kitl expression in the skin was the most effective for preventing hair graying and a significant effect was also confirmed for HGF and ET3 expression. The repeated hair plucking or shaving led to hair graying without any genetic lesion. Kitl is a more effective factor for prevention of hair graying than HGF or ET3. Our simple model of hair graying may provide a basic tool for screening the molecules or reagents preventing the progression of hair graying.     

Sebaceous carcinoma within rippled/carcinoid pattern sebaceoma

Although the histogenesis of sebaceous carcinomas remains unclear, the occurrence of intraepidermal or intraepithelial sebaceous carcinoma in the epidermis or conjunctiva may suggest de novo histogenesis. This report describes a case of sebaceous carcinoma within preexisting rippled/carcinoid pattern sebaceoma. This lesion was composed of two (benign and malignant) components, and the benign component of the lesion showed the typical features of a rippled/carcinoid pattern sebaceoma. Although evidence of trauma as well as a vertical orientation was seen in this lesion, the malignant component of the lesion showed histopathological evidence of malignancy (sebaceous carcinoma), such as the aggregations with irregular and infiltrated borders, a sheet‐like growth pattern, and the cytopathological findings of the neoplastic cells, showing a high‐grade of malignancy (a high mitotic index and abnormal mitotic figures). The immunohistochemical staining for p53, Ki‐67 and D2‐40 also favored this diagnosis. This sebaceous carcinoma component was considered to be the incipient stage of carcinoma within preexisting sebaceoma, therefore, it was still considered to be a vertically oriented lesion. This case shows the possibility that abnormal (malignant) sebaceous germinative cells may originate within a sebaceoma, thereby suggesting that some sebaceous carcinomas may develop from preexisting sebaceomas.     

Primary non-Hodgkin’s lymphoma of the gallbladder diagnosed by laparoscopic cholecystectomy

Primary lymphoma of the gallbladder is an exceedingly rare disease. We experienced an asymptomatic case of primary non-Hodgkin’s lymphoma of the gallbladder in a 55-year-old woman in whom laparoscopic cholecystectomy made a definite diagnosis. Abdominal computed tomography revealed a 4-cm gallbladder tumor with markedly enlarged lymph nodes in the retropancreatic area. Despite the marked involvement of lymph nodes, serum levels of carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 were not elevated. The discrepancy between the imaging findings and the patient’s mild clinical presentation led us to suspect that the tumor was a lymphoma. We examined serum markers of lymphoma, revealing slight elevations of interleukin (IL)-2 receptor and thymidine kinase. Laparoscopic cholecystectomy for a total biopsy was performed successfully, and the results of intraoperative frozen-section examination led us to have a high suspicion of malignant lymphoma. The final diagnosis was large diffuse B-cell lymphoma of the gallbladder with a positive CD20 antibody reaction. The patient received postoperative chemotherapy with R-CHOP (rituximab, 500 mg; cyclophosphamide, 1000 mg; adriamycin, 68 mg; vincristine, 1.9 mg; and prednisone, 80 mg) starting on postoperative day 12. She achieved complete remission and is still in complete remission 3 years and 2 months after the cholecystectomy. In conclusion, gallbladder lymphoma should be added to the differential diagnosis of gallbladder tumors, especially when the imaging findings and clinical presentation are not consistent with typical signs of gallbladder carcinoma, and laparoscopic cholecystectomy is helpful for the confirmation of suspicious cases.     

Adrenergic regulation of clock gene expression in mouse liver

A main oscillator in the suprachiasmatic nucleus (SCN) conveys circadian information to the peripheral clock systems for the regulation of fundamental physiological functions. Although polysynaptic autonomic neural pathways between the SCN and the liver were observed in rats, whether activation of the sympathetic nervous system entrains clock gene expression in the liver has yet to be understood. To assess sympathetic innervation from the SCN to liver tissue, we investigated whether injection of adrenaline/noradrenaline (epinephrine/norepinephrine) or sympathetic nerve stimulation could induce mPer gene expression in mouse liver. Acute administration of adrenaline or noradrenaline increased mPer1 but not mPer2 expression in the liver of mice in vivo and in hepatic slices in vitro. Electrical stimulation of the sympathetic nerves or adrenaline injection caused an elevation of bioluminescence in the liver area of transgenic mice carrying mPer1 promoter-luciferase. Under a light-dark cycle, destruction of the SCN flattened the daily rhythms of not only mPer1, mPer2, and mBmal1 genes but also noradrenaline content in the liver. Daily injection of adrenaline, administered at a fixed time for 6 days, recovered oscillations of mPer2 and mBmal1 gene expression in the liver of mice with SCN lesion on day 7. Sympathetic nerve denervation by 6-hydroxydopamine flattened the daily rhythm of mPer1 and mPer2 gene expression. Thus, on the basis of the present results, activation of the sympathetic nerves through noradrenaline and/or adrenaline release was a factor controlling the peripheral clock.