Masanobu Satoh

Expression of cytokine genes and presence of enteroviral genomic RNA in endomyocardial biopsy tissues of myocarditis and dilated cardiomyopathy.

Viral infection, especially by enteroviruses, has been considered to be the most common cause of myocarditis, which may progress to dilated cardiomyopathy (DCM). Although the mechanism of progression remains uncertain, a cytokine-associated injury of myocytes has been proposed. Using reverse transcriptase polymerase chain reaction (RT-PCR), we examined the expression of interleukin 1β (IL-1β), IL-6, IL-8 and tumour necrosis factor alpha (TNF-α) and the presence of enteroviral genomic RNA in endomyocardial biopsy tissues obtained from patients with myocarditis and DCM. We examined endomyocardial biopsy tissues obtained from 6 patients with myocarditis, 21 with DCM and 15 with non-infectious cardiac diseases as controls. In patients with myocarditis, endomyocardial biopsy was performed twice at an interval of 1 month to 8 years after the onset of myocarditis. We used RT-PCR to detect IL-1β, IL-6, IL-8 and TNF-α genes expression and nested RT-PCR (nRT-PCR) to detect enteroviral genomic RNA. IL-1β, IL-6, IL-8 and TNF-α genes were expressed in 100% (6/6) and enteroviral genomic RNA in 67% (4/6) of myocarditis patients at the first biopsy. At the second biopsy, IL-1β, IL-6, IL-8 and TNF-α genes were expressed in none, 50% (3/6), 67% (4/6) and 67% (4/6), respectively, and enteroviral genomic RNA in 67% (4/6). Four patients with myocarditis, in whom IL-8 and TNF-α genes and enteroviral genomic RNA were detected, progressed to DCM at the second biopsy. IL-1β, IL-6, IL-8 and TNF-α genes were expressed in none, 24% (5/21), 38% (8/21), 57% (12/21) of DCM patients, respectively. Enteroviral genomic RNA was detected in 43% (9/21) of DCM. Neither cytokine expression nor enteroviral genomic RNA were detected in the controls. The high incidence of cytokines, especially IL-6, IL-8 and TNF-α, expression in myocarditis and DCM, which might be induced by enteroviral infection, suggests that cytokines play an important role in myocytic damage leading to DCM.

Expression of bone morphogenetic proteins of human neoplastic epithelial cells

Bone morphogenetic proteins (BMPs) are crucial factors of osteogenesis. We investigated the expressions of BMP subtypes in human salivary adenocarcinoma cell line (HSG‐S8), tongue squamous cell (HSC‐4) and gingival squamous cell (Ca9‐22) carcinoma cell lines, gastric poorly differentiated adenocacinoma cell (MNK45) and signet ring cell (KATOIII) carcinoma cell lines, rectal adenocarcinoma (RCM‐1, RCM‐2, and RCM‐3), and thyroid (8505C) and bladder (T24) carcinoma cell lines by reverse transcription‐polymerase chain reaction (RT‐PCR). RT‐PCR disclosed that BMP‐1 was expressed in all cell lines examined, and BMP‐2 was amplified in almost all cells except MKN45. Two squamous cell carcinomas, HSC‐4 and Ca9‐22, and KATOIII expressed only BMP‐1 and BMP‐2. MKN45 did not express BMP‐2, but expressed BMP‐7 and weakly BMP‐4 and BMP‐5. In addition to the expression of BMP‐1 and BMP‐2, three rectal adenocarcinoma cell lines commonly expressed BMP‐7, and HSG‐S8 expressed BMP‐6. These findings indicated that the neoplastic epithelial cells possessed a rather great potency to express BMP mRNAs. On the other hand, among these carcinoma cells, HSG‐S8 solely induced bone in nude mouse tumors, and HSC‐4 and KATOIII contained many calcified masses in tumors while the rest did not induce either.

The expression of TNF-α converting enzyme at the site of ruptured plaques in patients with acute myocardial infarction

Background  Tumour necrosis factor‐α (TNF‐α) converting enzyme (TACE) plays an essential role in the TNF‐α shedding process, which could affect the outcome of acute myocardial infarction (AMI). However, it remains unclear whether it originates from the ruptured plaque or represents a systemic process. This study analysed TACE‐mediated TNF‐α shedding at the site of ruptured plaques in AMI patients and compared them with a systemic mechanism.

The Immunohistochemical Localization of Fas and Fas Ligand in Jaw Bone and Tooth Germ of Human Fetuses

Abstract The cellular localization and roles of bone morphogenetic protein (BMP)-2 and apoptosis-associating factors in human orofacial development remain unclear. In this study, BMP-2, osteocalcin, and TGF-β, which are bone-differentiating markers, apoptosis-associating factors (i.e., Bcl-2, Bax, Fas, and Fas ligand), apoptotic cells detected by the in situ 3′-end labeling method (TUNEL), and proliferating cell nuclear antigen (PCNA) were immunohistochemically examined in the heads (in particular, the jaw bone and tooth germs) of human fetuses of 11-week pregnancy. BMP-2 was positive in osteoblasts and newly formed osteoid of the incisive and palatal bone of the maxilla and the mandible, which indicated that BMP-2 was exclusively involved in intramembranous ossification in the human fetal head. Fas was positive in the cytoplasm of osteocytes and a few osteoblasts. In contrast, Fas ligand was positive in the cytoplasm of osteoblasts and abundant in the stroma of the osteoblastic layer, periosteum, and perichondrium. The Fas ligand in the stroma was recognized as the soluble form, which was possibly produced by osteoblasts. TUNEL-positive apoptotic cells were found in a few osteocytes and a few osteoblastic cells in new bone, and in monocytes of degenerate Meckels cartilage. The induction of apoptosis observed in monocytes seems to be caused via a Fas-Fas ligand cell death system, because some of these monocytes were Fas-positive, and most of them were Fas ligand-positive. Interestingly, the abundant soluble Fas ligand observed in the periosteum probably protects the bone-formative zone from the invasion of the activated lymphocytes by binding to Fas expressing in these lymphocytes and killing these cells. Fas and Fas ligand were focally positive in the dental lamina and inner enamel epithelium and cusps of the enamel organ, nevertheless, the presence of TUNEL-positive cells was very rare. Bcl-2 was clearly and Bax was weakly positive in the cells throughout the dental lamina and enamel organ. These findings indicated that Fas-mediated apoptosis was inhibited by the Bcl-2 family in the development of teeth.

Harderianization is another sexual dimorphism of rat exorbital lacrimal gland.

The exorbital lacrimal glands (ELG) of rats were examined for both sexes to determine what degree of harderianization occurred as a function of age and after castration, and to investigate its time course and origin in ELG. Light microscopically, very small Harderian foci were seen in the ELG of both sexes at 3 weeks of age. As the male rats became older, the relative volume of the Harderian gland (HG) cells in the ELG increased. At age 6 months, the value was 1.25 +/- 0.31% in males and 0.13 +/- 0.05% in females (p less than 0.05). After castration, a significant decrease (0.21 +/- 0.01%, p less than 0.05) was observed in that of male ELG. In contrast, in female ELG, HG cells were inconspicuous and the relative volume of those did not vary during this experimental period or after castration. It appeared that the HG cells had developed from undifferentiated basal cells of the acini and the intercalated ducts in the ELG at age 2-6 months. Then, at age 22 months, they also probably developed from those of the excretory ducts of the ELG.

Pigmented ameloblastic fibrodentinoma: a novel melanin-pigmented intraosseous odontogenic lesion

Abstract This paper reports about an ameloblastic fibrodentinoma with macroscopically visible pigmentation, resulting in the clinical appearance of a melanotic lesion in a 21-year-old Japanese male. In addition to the characteristic histopathologic features of ameloblastic fibrodentinoma, various-formed and -sized cells, which were considered to be melanophages containing numerous aggregates of melanin pigment in their cytoplasm, were densely distributed throughout the mesenchymal component. In addition, melanin pigment was deposited in dentin. Some of the pigmented cells showed dendritic form and were regarded as melanocytes. Furthermore, pigmented cells were frequently distributed in the epithelial component, and melanin pigment was seen in some epithelial cells. Perusal of the English language literature revealed 30 cases of pigmented odontogenic tumors: 18 were calcifying odontogenic cysts, three were ameloblastic fibro-odontomas, three were adenomatoid odontogenic tumors, two were odontomas, one was an ameloblastic fibroma and one was an odontogenic fibroma. However, all of these reported lesions did not show macroscopically visible pigmentation. The possible histogenesis of melanocytes in the odontogenic lesions is discussed, although no firm conclusion could be drawn.

Congenital leiomyomatous epulis: a case report with immunohistochemical study.

The histologic and immunohistochemical findings of an extremely rare case of congenital soft tissue mass on the alveolar ridge in an infant are reported. The lesion clinically mimicked an ordinary congenital epulis (congenital granular cell epulis, granular cell tumor of the newborn); however, histologically it consisted of a conglomerate of spindle‐shaped cells, akin to smooth muscle cells, which formed interlacing and whorled fasciculi. Nerve fibers with myxoid degeneration, capillaries and muscle walled small vessels intermingled with fasciculi of spindle‐shaped cells. The border between the conglomerate of spindle‐shaped cells and the surrounding connective tissue was not evident. Immunohistochemically, most of the spindle‐shaped cells were intensely positive for antibodies to alpha‐smooth muscle actin, HHF‐35 and desmin. These findings suggest that the lesion was composed of mature smooth muscle cells that were of hamartomatous or choristomatous nature. The term ‘congenital leiomyomatous epulis’ is proposed.

Virus-like particles in the follicular epithelium of the thyroid from a patient with subacute thyroiditis (De Quervain).

The author experienced a case of subacute thyroiditis (de Quervain) in a 36‐year‐old female. Electron microscopic examination of the thyroid tissue of the patient revealed virus‐like particles (VLP) in the degenerated follicular epithelium. Judging from the size, the VLP corresponded to the influenza or mumps virus.

Sialolith of the submandibular gland with bone formation

An unusual case of sialolith with bone formation, occurring in the submandibular gland of a 33‐year‐old woman, is reported. In addition to the irregularly laminated structure of sialolith, sparsely scattered foci of bone tissue were found. Some of them were mature, lamellar bone with lacunae containing osteocytes, endosteum and a bone marrow‐like element. Others were immature bone associated with or without multinucleated giant cells. Foci of bone tissue were in contact with caliculi or fibrous tissue, and no epithelial component was seen around them. These observations suggest that bone formation in the present case may be in the nature of pathological ossification, and that in the earlier stage, the bone that is deposited is woven and is replaced through successive remodeling cycles by lamellar bone. This is the first case of sialolith with bone formation, although sialolithiasis is a common disease of the salivary glands.

Alveolar Bone Loss of Senescence-accelerated Mouse (SAM)

SAM-R/1/Iw (senescence-accelerated mouse, resistant) and Pl2/Iw (senescence-accelerated mouse, prone) under a conventional environment and eating standard pellets were examined for alveolar bone loss and the presence of periodontitis around maxillary and mandibular molars as a function of age. Neither SAM strain manifested a chronic periodontitis similar to that in humans, and no obvious plaque and calculus were observed. However, in both strains, 15% of M3 was lost after 13 months of age, and alveolar bone loss gradually increased with advancing age. Though there was no significant difference in the incidence of M3 loss between the two strains, P/2/Iw showed a higher alveolar bone loss around all molars than did Rl1/ Iw after one month of age throughout their life span. For Ml, the difference in alveolar bone loss between Pl2/Iw and Rl1/Iw was significant, and it was probably caused by the difference in degree of molar eruption. Other factors, such as occlusal trauma and gingivitis, may play some role in alveolar bone loss.