Effect of occlusal rehabilitation on spatial memory and hippocampal neurons after long-term loss of molars in rats.

Experimental loss of occlusal support caused by the extraction or grinding of molar teeth has been reported to foment the impairment of learning and memory in laboratory animals. The purpose of this study was to examine the effect of occlusal reconstruction after long-term loss of molars on spatial memory by using 8-arm radial maze and by assessing histopathological changes of neuron density in the hippocampus. Experimental dentures were inserted into the oral cavities of molarless rats to recover the occlusal support. Age-matched groups of control, molarless and denture-wearing rats were trained to perform the maze tasks. The difference of the error incidence in the maze task was evaluated between three groups. The difference of neuron density between three groups was also evaluated at the end of the maze task. Serum corticosterone levels were also measured to estimate the chronic stress, which could be caused by extraction, insertion of the experimental denture or any experimental procedure. The error incidence in the denture-wearing group was significantly higher than that of the control group, but significantly lower than that of the molarless group. Significant differences of neuron density were observed between three groups in each of the hippocampal CA1, CA3 and DG subfields. No significant difference of the serum corticosterone levels between three groups could be observed. From the results of this study, it was suggested that the recovery of occlusal support would bring amelioration of cognitive impairment concomitant with long period loss of molars in rats.

Central odontogenic fibroma with amyloid: a diagnostically challenging case.

Odontogenic fibroma is a rare benign mesenchymal odontogenic tumor, with its histological diversity possibly posing diagnostic challenges. A case of the amyloid variant of central odontogenic fibroma, with epithelial cells in perineural and intraneural locations, is reported herein. The 46-year-old female patient had experienced discomfort related to her anterior right hard palate for approximately 25 years. Clinical examination revealed a depression in the anterior hard palate, and radiographic examination showed a well-defined radiolucent lesion with root resorption of the adjacent teeth. Histologically, the well-circumscribed tumor was composed of hypocellular collagenous connective tissue with small islands of odontogenic epithelium. In addition, the juxta-epithelial deposition of amyloid globules without calcification and epithelial cells in perineural and intraneural locations were observed, which posed a diagnostic challenge in differentiating the lesion from the non-calcifying variant of calcifying epithelial odontogenic tumor and sclerosing odontogenic carcinoma. However, on the basis of the clinical and radiographic findings, which were suggestive of a benign and slowly progressive process given the corticated, unilocular radiolucency, the considerable root resorption, and the long history of this finding in an otherwise healthy patient, the final diagnosis was amyloid variant of central odontogenic fibroma. Increased recognition of this variant of odontogenic fibroma and its differentiation from other more aggressive lesions could help the clinician to avoid overdiagnosis and overtreatment.

Expression of Lewisa, Lewisb, Lewisx, Lewisy, siayl-Lewisa, and sialyl-Lewisx blood group antigens in human gastric carcinoma and in normal gastric tissue.

A panel of 6 mouse monoclonal antibodies detecting blood group antigens of the Lewis systems and their sialylated derivatives have been used to define the immunoanatomic distribution of these antigenic structures within the normal human gastric mucosa and in gastric cancer tissues. The reagents employed detect the following blood group specificities: Lewisa, Lewisb, Lewisx, Lewisy, sialylated Lewisa, and sialylated Lewisx. We have analyzed the presence of these antigens in histologically normal gastric mucosa and in gastric carcinoma from 61 patients by the immunoperoxidase method. In addition, we simultaneously examined the blood group and secretor status in 31 of the 61 individuals studied. Immunohistochemical analysis revealed that these antigenic systems are differentially expressed in cell types and cell layers of the normal gastric epithelium. Major differences were observed in surface epithelia and in deep glands including Brenner's gland of the gastroduodenal junction, mainly in the pronounced expression of Lewisa and Lewisb antigens in the former and the expression of Lewisx and Lewisy in the latter. In secretor individuals, Lewisb was the dominant antigen in the surface epithelium, and in nonsecretors, Lewisa was observed in the surface epithelium, Lewisx and Lewisy were both detected in the deep glands and in Brenner's glands regardless of the secretor status. The expression of sialylated derivatives in normal gastric tissues was considerably reduced but was consistent with the expression of their precursors in normal gastric epithelium. In gastric cancers, more pronounced expression of Lewisa and sialylated Lewisa was observed in secretor individuals and acted as a tumor-associated antigen. Comparison of the plasma level of sialylated Lewisa and its tissue expression demonstrated that the shedding of the antigen into interstitial stroma correlated with the detection of the antigen in serum. These studies confirmed the importance of blood group antigens as normal differentiation antigens. Examination of secretor status clarified the mechanism of Lewisa and Lewisb antigen expression in gastric surface epithelium. Alterations in the expression of these antigens and an increase of sialylated derivatives in gastric cancers demonstrated that these blood group antigens are useful tools for the analysis of histogenesis and organogenesis in the stomach and its neoplastic and nonneoplastic diseases.

Clinical characteristics of halitosis: differences in two patient groups with primary and secondary complaints of halitosis.

Halitosis, defined as an unpleasant oral odor, has become a health concern among the general public. The objective of this study was to evaluate the diversity of clinical characteristics of halitosis of the patients who visited dental clinics. Sixty-eight patients with primary complaints of halitosis and 19 patients with primary complaints of periodontal diseases but secondary complaints of halitosis were studied by organoleptic examination. The patients with primary complaints were diagnosed as having halitosis in fewer cases than the patients with secondary complaints-25% and 53%, respectively. Patient complaints for halitosis were further categorized, by questionnaire, into three types: Type 1, self-conscious; Type 2, conscious by the indication of others; and Type 3, conscious by presumptions from the attitude of others. Although 80% of the patients of both groups were of Type 1, only 24.1% of the Type 1 patients with primary complaint, in comparison with 50% of the Type 1 patients with secondary complaint, were actually found to have halitosis. The results suggest that the majority of patients with primary complaints of halitosis at the dental clinic did not actually have halitosis, but suffered from an imaginary halitosis due to presumptions based upon others' attitudes. After treatment, these patients were more likely to be dissatisfied than patients who had visited the clinic with halitosis as their secondary complaint.

Inhibitory effect of lignin-related pine cone extract on cell proliferating enzyme activity of spontaneous mammary tumours in mice.

A lignin-related cone extract of pine (Pinus parviflora Sieb et Zucc) (FrVI) or a synthetic lignin (DHP-FA) (175 micrograms/0.1 ml 0.9% NaCl solution) was injected intravenously to SHN mice bearing spontaneous mammary tumours three cycles each with consecutive 3 days of treatment and 4 days of interruption. Activities of both thymidylate synthetase (TS) and thymidine kinase (TK), i.e., DNA synthesizing enzymes in de novo and salvage pathways of pyrimidine metabolism, respectively, were apparently decreased in mammary tumours of FrVI-treated mice compared to those of the control mice bearing tumours without treatment. While the percent change of mammary tumour size during the experiment differed little among groups, both FrVI and DHP-FA prevented tumours from ulceration. Furthermore, the development and growth of preneoplastic mammary hyperplastic alveolar nodules were decreased by the treatments of both agents. They showed no toxicity. All results suggest that these lignin-related compounds, especially FrVI, may be useful as chemopreventive agents, with some improvement of administration method, and/or for employment in combination with any other agents.

Expression of p53 protein and Ki-67 antigen in gingival hyperplasia induced by nifedipine and phenytoin.

BACKGROUND: Although it has been thought that drug-induced gingival hyperplasia is not related to tumorigenesis, recent case reports have shown that squamous cell carcinomas may arise in gingival hyperplasia induced by cyclosporin and phenytoin. The possible implications between the pathogenesis of this disease and tumorigenesis have not been elucidated and remain to be studied. METHODS: We immunohistochemically examined the expression of tumor-related markers such as p53 protein and Ki-67 antigen in 11 hyperplastic gingival tissues induced by nifedipine and phenytoin, as well as 5 control tissues using an avidin-biotin-peroxidase complex method. RESULTS: Two specimens out of 4 nifedipine-induced and 4 out of 7 phenytoin-induced hyperplastic gingival tissues revealed the expression of p53 protein in the nuclei of epithelial cells, while no expression of p53 protein was observed in the epithelia of the 5 non-hyperplastic control tissues. The immunoreactions against p53 protein showed sporadic distribution in the suprabasal layers of hyperplastic epithelia. The mean percentage of epithelial cells expressing Ki-67 antigen in the hyperplastic gingival tissues was more than 10% higher than that in the controls. The expression of Ki-67 antigen was suppressed in the typical rete pegs deeply elongated into lamina propria of hyperplastic gingival tissues. Intense immunostaining of Ki-67 antigen was found in fibroblasts of hyperplastic gingival tissues, while that of the control tissues was negligible. CONCLUSIONS: The expression of p53 protein in gingival hyperplasia suggests that the pathogenesis of this disease is involved with impaired DNA, while the growth arrest observed in the hyperplastic epithelia with typically elongated rete pegs as expressed with Ki-67 antigen may prevent the invasive expansion of epithelial cells undergoing DNA damage within gingival tissues and may consequently suppress tumorigenic progression.

Immunolocalizaiton of c-Myc and bcl-2 proto-oncogene products in gingival hyperplasia induced by nifedipine and phenytoin.

BACKGROUND: Hyperplastic gingival tissues show the histopathological characteristics of thick parakeratinized squamous epithelia with acanthosis and rete pegs elongated into the lamina propria. However, the pathogenic factors that contribute to the epithelial morphogenesis of this disease are obscure and remain to be studied. METHODS: We immunohistochemically examined the expression of both c-Myc and bcl-2 oncoprotein, which can exert influence on the epithelial morphogenesis and homeostasis, in 12 hyperplastic gingival tissues induced by nifedipine and phenytoin as well as 5 control tissues using avidin-biotin-peroxidase complex methods. RESULTS: Four specimens out of 5 nifedipine-induced and 5 out of 7 phenytoin-induced hyperplastic gingival tissues revealed the expression of c-Myc oncoprotein, whereas no significant immunostaining of c-Myc oncoprotein was found in 5 control tissues. The c-Myc oncoprotein-positive cells were observed to be localized in the basal and suprabasal cell layers of the hyperplastic gingival epithelia. Although all of the 12 hyperplastic gingival epithelia showed the distribution of bcl-2 oncoprotein in the basal and suprabasal layer cells, in 5 control epithelia the bcl-2 oncoprotein expression was slight and confined to the basal layer cells. CONCLUSIONS: The results of our present study indicate that the synergistic overexpression of c-Myc and bcl-2 oncoprotein may be related to the pathogenesis of gingival hyperplasia induced by nifedipine and phenytoin, especially to the morphogenesis of hyperplastic epithelia.

Correlation between measurements using a new halitosis monitor and organoleptic assessment.

Halitosis is known as unpleasant oral odor and is a health concern among the general public. Previously, we reported on a new portable monitor with a zinc-oxide, thin-film, semiconductor sensor which demonstrated simplicity of handling, high reproducibility and correspondence for organoleptic assessment. The results suggested its usefulness for the diagnosis of halitosis. Using the monitor, oral air samples of 94 subjects were measured in a field survey, and the values were compared with the organoleptic rates of corresponding samples assessed by two judges. A highly significant correlation (r = 0.824, P < 0.01) was demonstrated between the measures obtained by the two methods. The results suggest that the monitor is useful for not only a clinical study but also a field study of halitosis.

A new monitor with a zinc-oxide thin film semiconductor sensor for the measurement of volatile sulfur compounds in mouth air.

Halitosis, defined as unpleasant oral odor, is a concern among the general public. Halitosis is generally diagnosed by organoleptic examination and by gas chromatographic analysis of the main source of halitosis, volatile sulfur compounds, such as hydrogen sulfide, methyl mercaptan, and dimethyl sulfide. Gas chromatography requires a large-scale system and a long running time. We investigated the use of a zinc-oxide thin film semiconductor sensor for measuring trace volatile sulfur compounds in mouth air. Mouth air samples collected in teflon bags from 21 volunteers were analyzed by 3 methods: the monitor analysis, gas chromatography, and organoleptic examination by 3 judges. The readings of the monitor were correlated with the values of the total volatile sulfur compounds measured by gas chromatography (r = 0.75, P < 0.01) and also with the organoleptic scores given by the judges (r = 0.76, P < 0.01). The organoleptic scores were correlated with the gas chromatographic values (r = 0.71, P < 0.01). These results suggest that this new monitor with a zinc-oxide thin film semiconductor sensor may be used for the diagnosis of halitosis. Its small size and simplicity of handling may enable its use for routine chair-side study and field surveys of halitosis.

Recovery of an impalement and transfixion chest injury by a reinforced steel bar.

A 36-year-old man was admitted to our hospital because of impalement injury due to a downwards fall upon some reinforced steel rods. An emergency operation was performed using percutaneous cardiopulmonary support (PCPS). The steel rods were taken out in the operating room. The heart, great vessels, vertebrae, and spinal cord were not involved in the impalement wounds. We performed a bronchoplasty of the torn and separated right main bronchus, and repaired the impaled left lung without any pulmonary resection. He recuperated without sequelae.

Mouse bone collagenase inhibitor: purification and partial characterization of the inhibitor from mouse calvaria cultures.

The organ culture of neonatal mouse calvaria produced both collagenase and collagenase inhibitor. The inhibitor was purified by a series of column chromatographies: DEAE-cellulose and CM-cellulose ion-exchange chromatography, concanavalin A-Sepharose and heparin-Sepharose affinity chromatography, and finally by Sephacryl S-200 gel filtration. The purified inhibitor migrated as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and had a molecular mass of 28,000. The inhibitor was purified 140-fold to a specific activity of 163 units/mg with a yield of 18% over the first step of the purification by DEAE-cellulose chromatography. The inhibitor stained positively for carbohydrate with periodic acid-Schiff's reagent indicating, in conjunction with its affinity to concanavalin A, that the inhibitor is a glycoprotein. In addition to mouse bone collagenase, this inhibitor also inhibited chick bone, rat bone, rabbit corneal, and human gingival collagenase, but did not inhibit bacterial collagenase.

HLA class II alleles and salivary numbers of mutans streptococci and lactobacilli among young adults in Japan.

To investigate the genetic predisposition toward the accumulation of oral microorganisms, the association between the alleles of HLA-DQA1, -DQB1 and -DRB1 and the salivary numbers of mutans streptococci and lactobacilli were examined in 102 young adults in Japan. HLA-DQA1*0102, DQB1*0604, DRB1*0802, and DRB1*1302 were weakly associated with the numbers of lactobacilli in saliva samples (P<0.05). HLA-DQB1*0601 was associated with the salivary numbers of mutans streptococci (P<0.01). Two HLA class II haplotypes, HLA-[DRB1*0802-DQA1*0301-DQB1*0302] and HLA-[DRB1*1302-DQA1*0102-DQB1*0604], were also weakly associated with the salivary numbers of lactobacilli (P<0.05). These observations suggest that HLA class II alleles may be related to the salivary populations of oral microorganisms, such as mutans streptococci and lactobacilli.