Presence of ghost cells and the Wnt signaling pathway in odontomas

BACKGROUND: Although it has been reported that ghost cells are present in odontomas, the generation mechanism of these cells is unclear. To evaluate the presence of ghost cells and involvement of the Wnt signaling pathway, we examined the expression of hard keratins, beta-catenin and Lef-1 in odontomas. METHODS: Sixty-nine cases of odontoma were examined immunohistochemically with the use of antibodies against human hair proteins, beta-catenin and Lef-1. RESULTS: Expression of hard keratins was found only in the cytoplasm of ghost cells in 46 (66.7%) of the 69 odontomas. Compound odontomas (78.8%) showed a higher incidence of ghost cells than complex odontomas (29.4%). Histopathologically, ghost cells were found within odontogenic epithelium adjacent to immature enamel and in the centre of Liesegang-ring-like calcified materials. Expression of beta-catenin and Lef-1 was observed in the cytoplasm and nucleus of odontogenic epithelial cells adjacent to the ghost cells in immature odontomas. CONCLUSION: These findings suggest that odontoma is a hard keratin-expressing tumor-like lesion, and that the Wnt signaling pathway may be involved in the formation of ghost cells in odontomas.     

Relationship of Diet to Small and Large Adenomas of the Sigmoid Colon

The relation of dietary factors to the risk of adenomas of the sigmoid colon was examined in men receiving a retirement health examination at the Self-Defense Forces Fukuoka Hospital between October 1986 and 1990. A total of 187 adenoma cases and 1557 controls with normal colonoscopy were identified in the series. Cases were further classified into small-adenoma (<5 mm, n=78) and large-adenoma (≥5 mm, n=67) groups. The consumptions of selected foods and beverages were ascertained before colonoscopy by means of a self-administered questionnaire. After adjustment for smoking, alcohol use, rank and body mass index, low rice consumption and high meat intake were independently associated with an increased risk of large adenomas. The risk of small adenomas was not related to either rice consumption or meat intake. Adjusted odds ratios of large adenomas for the low, intermediate and high consumption levels of rice were estimated to be 1.0 (referent), 0.83 and 0.43, respectively (trend P = 0.08), and the corresponding figures for meat consumption were 1.0 (referent), 1.58 and 2.38, respectively (trend P =0.02). The findings suggest that low rice consumption and high meat intake may promote the growth of colon adenomas, thereby increasing the risk of colon cancer.     

MR appearances of urinary bladder in amyloidosis associated with multiple myeloma

Amyloidosis led to thickening of the urinary bladder wall, with hypointensity in T2-weighted images, which was distinguished from multiple myeloma involvement. Received: 3 April 1995/Accepted: 7 August 1995     

Action of intravenously administered talipexole on the rat striatal neurons receiving excitatory input from nigral dopamine neurons

Electrophysiological studies using rats anesthetized with chloral hydrate were performed to elucidate whether or not intravenously injected talipexole acted as a D₂ receptor agonist on the striatal neurons in comparison with the action of bromocriptine. The activities of the striatal neurons were extracellularly recorded using a glass microelectrode attached along a seven-barreled micropipette, each barrel of which was filled with talipexole, bromocriptine, SCH23390 (D₁ antagonist), domperidone (D₂ antagonist), glutamate or 2 M NaCl. These drugs were iontophoretically applied to the immediate vicinity of the target neuron being recorded. The effects of talipexole and bromocriptine were examined on the neurons, whose spikes (induced by the stimulation of the substantia nigra pars compacta) were inhibited by the iontophoretic application of domperidone. Iontophoretic application of talipexole or bromocriptine increased spontaneous firing of these neurons and this increase in firing was also inhibited by iontophoretically applied domperidone. In the same neurons, intravenously administered talipexole (0.01, 0.02 and 0.04 mg/kg) dose-dependently increased firing, and this increase was inhibited by microiontophoretically applied domperidone, but not by SCH23390. On the other hand, the intravenous injection of bromocriptine (0.1, 0.2 and 0.4 mg/kg) also increased the firing rate. However, the increase was not dose-dependent and fluctuated; the firing transiently decreased during the increase in firing with intravenously administered bromocriptine. However, the bromocriptine-induced increase in firing was also suppressed by domperidone, and decrease in firing was inhibited by SCH23390. These findings suggest that talipexole acts as a D₂ agonist on the striatal neurons receiving input from substantia nigra pars compacta and increases firing when intravenously applied. However, intravenously administered bromocriptine appears to act as both a D₂ agonist and probably as a D₁ agonist on the striatal neurons to increase and decrease firing, respectively.     

Multiple osteonecrosis associated with allergic dermatitis

Summary A case of multiple osteonecrosis including both shoulders, hips, and knee joints and the right fourth metatarsophalangeal joint is reported.     

Preliminary Report on Teratogenic Effects of Zonisamide in the Offspring of Treated Women with Epilepsy

Summary: Purpose: We wished to assess the risk of terato-genicity of zonisamide (ZNS) in humans.
Methods: Pregnant epileptic women treated with ZNS and their offspring were prospectively monitored from June 1989 to December 1994. The outcome of pregnancy and status of neonates were examined based on the same standardized protocol.
Results: Twenty-six offspring exposed to ZNS with or without other antiepileptic drugs (AEDs) were studied. Malformations were detected in 2 offspring (7·7%) exposed to ZNS polypharmacy. Anencephaly was detected in one case at 16 weeks of gestation (case 1, artificial abortion), and atrial septa1 defect was detected in another case at 37 weeks of gestation (case 2, delivery by cesarean section). Serum concentrations of ZNS during the first trimester of pregnancy were 6·1 μg/ml in case 1 and 6·3μ/ml in case 2; in both cases, the levels were below the therapeutic concentration range of ZNS.
Conclusions: Teratogenic effects of ZNS were not clearly defined from these results since malformations were detected in two polypharmacy cases but not in four monopharmacy cases. The present data do not indicate that the risk of ZNS teratogenicity is greater than that of other conventional AEDs. However, such risk cannot be neglected even at therapeutic dosages or concentrations of ZNS, especially in patients receiving polypharmacy.     

Internalization of Mycobacterium bovis Bacillus Calmette-Guérin into Osteoblast-Like MC3T3-E1 Cells and Bone Resorptive Responses of the Cells against the Infection

Mycobacterium bovis BCG (BCG) is a live vaccine used worldwide against tuberculosis. However, it has unfavourable side effects such as osteitis or osteomyelitis, and these sometimes lead to vertebral caries in some patients as a result of bone resorption. Osteoblasts might play a role in the bone resorption caused by BCG infection, because they are central cells in bone metabolism. Cultured osteoblast-like cell lines (MC3T3-E1) derived from C57BL mice susceptible to BCG infection cells were infected with BCG at several doses. Interestingly, internalization of BCG-enveloped phagosome-like membrane in osteoblast-like cells were observed by transmission electron microscopy (TEM). Owing to infection, the proliferation and alkaline phosphatase activity of the osteoblast-like cells were reduced in a dose-dependent manner. On the other hand, interleukin (IL)-6 production was considerably enhanced by infection. These results suggest that BCG infects osteoblasts, suppressing their proliferation and differentiation and inducing bone resorption, which may be related to osteitis/osteomyelitis and bone caries caused by BCG infection.