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Biomedical subjects

G Yamane

Publications and source records attributed to G Yamane.

At least 19 recordsLinked to original sources
PubMed2003

Langerhans' cells in the murine oral mucosa in the inductive phase of delayed type hypersensitivity with 1-chloro-2, 4-dinitrobenzene.

We created a murine model of delayed-type hypersensitivity (DTH) to 1-chloro-2, 4-dinitrobenzene (DNCB). Using this murine model, we compared oral mucosal sensitization and skin sensitization for the difference in reaction during the elicitation phase. Evaluation of sensitizability, using the mouse ear swelling test (MEST) after oral mucosal or skin sensitization, showed that the ear swelling response peaked 24 h after challenge. The optimal induction concentration was 1.0% in both oral mucosal and skin sensitization, resulting in a positive reaction rate of 100%. However, the ear swelling response 24 h after challenge with the optimal concentration of DNCB (1.0%) was significantly lower in oral mucosal than in skin sensitization. We compared the oral mucosal and skin sensitization sites for the number of Langerhans' cells (LC) and the antigen-presenting capability in the induction phase. The numbers of F4/80+ major histocompatibility complex (MHC) class II+ LC before induction did not differ significantly between the oral mucosa and the skin. After induction, F4/80+ MHC class II+ LC increased in number, but the increase was significantly smaller in the oral mucosa than in the skin. MEST on anti-CD86 antibody-administered mice showed that ear swelling was similarly suppressed after oral mucosal or skin sensitization. In murine models of DTH after oral mucosal sensitization, the number of F4/80+CD86+ LC increased after induction, but the increase was significantly smaller than that in murine models of DTH after skin sensitization. This study showed that, in murine models of DTH, oral mucosal sensitization elicited a weaker reaction than skin sensitization. This was presumably because oral mucosal sensitization induced fewer LC, resulting in lower antigen-presenting capability.

Animals↗
PubMed2002

Investigation of environmental factors for diagnosing malignant potential in oral epithelial dysplasia.

A study was conducted in rats with early tongue carcinoma induced by 4-nitroquinoline 1-oxide (4NQO), in order to investigate the early diagnosis of malignant potential of epithelial dysplasia. The rat tongue lesions were classified by their severity into three groups corresponding to early cancer, dysplasia and no change. The grade of epithelial changes was determined according to 13 items of WHO Epithelial Dysplasia Criteria. The expression levels of p53 and Bcl-2 proteins were detected immunohistochemically, and apoptotic cells were detected using the TUNEL method. In addition, a p53 mutation by lesions was detected. The expression ratio of p53 protein was high in dysplasia, and the ratio of Bcl-2 protein was high in early cancer and dysplasia. The TUNEL-positive cells were observed primarily in the granular layers of the no change cells, and their numbers decreased as the cells shifted to the early cancer stage. The p53 mutation was detected using a microdissection method in dysplasia, where it was found in three out of nine lesions. All the mutations in dysplasia detected were on the same codon that was found to be mutated in the early cancer. These results indicate that the association between the p53 mutation and histological changes in carcinogenesis epithelial dysplasia is strong, and that both the identification of p53- and Bcl-2-positive epithelium, and decrease in the TUNEL positive ratio, were useful for the diagnosis of the malignant potential of precancerous lesions.

4-Nitroquinoline-1-oxide↗
PubMed2001

Clinicostatistical study of ameloblastoma treatment.

The purpose of this study was to investigate the treatment of 190 cases of ameloblastoma in our department from 1966 to 1994. The statistical results with regard to age, sex and region agreed with those of other investigators. Thirty-five of 43 (81.4%) cases underwent enucleation in 1960s, but the sixteen of 27 (59.3%) cases underwent partial resection of mandible in 1990s. The defect of mandible was reconstructed with iliac bone grafting since 1968, grafts with a mixture of iliac blocked bone and PCBM (particulate cancellous bone and marrow) have been used since 1975. Grafting of the inferior alveolar nerve with the great auricular nerve to the defect has been performed in our department since 1977. Recently, technique involving pull-through of the inferior alveolar nerve bundle has been used in our department. When the reconstruction method for the mandible and nerve has been established, it becomes possible to operate radically and positively. Recurrence occurred in 17 cases after the primary enucleation. It is thought that the primary treatment of ameloblastoma must be as radical as possible. It appears to be necessary to observe progress and perform follow-up in cases of ameloblastoma for more than ten years, because there was one recurrence at 9 years and 4 months after the first operation. In fact, three quarters of our cases were lost to follow-up. Such losses can problems in confirming recurrence and responding rapidly.

Adolescent↗
PubMed2000

Relationships between the onset of pustulosis palmaris et plantaris, periodontitis and bacterial heat shock proteins.

Relationships between the onset of pustulosis palmaris et plantaris, periodontitis and heat shock proteins were studied by using enzyme-linked immunosorbent assay to examine levels of immunoglobulin G (IgG) against Escherichia coli GroEL, a recombinant DnaJ of Actinobacillus actinomycetemcomitans heat shock protein, a synthetic peptide made from the 180th to the 188th amino acids of Mycobacterium bovis BCG Hsp65, and a recombinant human Hsp60, in sera obtained from 43 pustulosis palmaris et plantaris patients judged to have chronic infectious diseases of the oral cavity. We found that the titers of IgG against E. coli GroEL and A. actinomycetemcomitans DnaJ in the sera from pustulosis palmaris et plantaris patients were significantly higher than those in the control group, whereas the titers of IgG against the synthetic M. bovis Hsp65 and the recombinant Hsp60 did not differ significantly. Periodontal therapy and extraction of teeth with periapical infectious resulted in remission of pustulosis palmaris et plantaris and a statistically significant reduction in the levels of IgG against E. coli GroEL in 9 of the 22 patients (41%) examined. We also found that the IgG levels against A. actinomycetemcomitans DnaJ in 6 serum samples of 16 (37%) were reduced, but not significantly, after the treatment. These results suggest that the IgG responses to heat shock proteins partially induced by oral bacteria may be related to the onset of pustulosis palmaris et plantaris in some patients.

Adult↗
PubMed1998

A clinical analysis of the recovery from sensory disturbance after sagittal splitting ramus osteotomy using a Semmes-Weinstein pressure aesthesiometer.

A number of studies of evaluation methods for sensory disturbance after sagittal splitting ramus osteotomy (SSRO) are known. To compare postoperative sensory disturbances among patients in different hospitals, a highly reproducible and standardized sensory test is required. In the present study, we measured the tactile threshold in the region innervated by the mental nerves in 45 patients (90 sides) after SSRO using a Semmes-Weinstein pressure aesthesiometer. The percentage of recovery to the normal level defined by Bell was 72.2% at one week, 82.2% at 4 weeks, and 90.0% at 8 weeks after SSRO. The recovery process was evaluated by classifying the postoperative sensory disturbance into 5 grade levels according to Bell's interpretation scale. The results showed that the SW sensory test is useful for evaluation of the recovery process from sensory disturbance after SSRO. Some improvements of this test were also discussed.

Adult↗
PubMed1997

A case of desmoplastic ameloblastoma of the maxilla.

A case of desmoplastic ameloblastoma of the maxilla is presented. The tumor showed characteristic radiographical and histological features. Radiographically, the tumor showed a mixed radiolucent-radiopaque lesion occupying the left maxillary sinus with undefined borders in the alveolar process. Histopathologically, the tumor was characterized by abundant, densely collagenous stroma with small nests and strands of odontogenic epithelium and bone tissues. Findings during operation suggested that the tumor arising in the alveolar process had grown upwards and almost displaced the left maxillary sinus. Complete resection is recommended for this variant because of the possibility of tumor infiltration into the surrounding bone marrow spaces.

Aged↗
PubMed1996

Transposition of the mental nerve and inferior alveolar nerve trunk.

Transposition of the mental nerve trunk is performed as a preprosthetic procedure. It is effective for patients with hyperesthesia caused by dental prosthesis and resorption of the alveolar ridge caused by aging. It is also performed to protect a location for implant insertion and to preserve the inferior alveolar nerve during mandibular tumor excision surgery. The demand for this surgery is increasing. The disadvantages of the surgery performed with the usual methods include the difficulty of the procedure and the long operation time. In an attempt to solve these problems, this study was conducted at the Department of Oral and Maxillofacial Surgery, Medical University Hanover, introducing an improved surgical method and presenting the actual operation performed in our department. This surgical method is considered superior because it is easy to perform, requires no special equipment and results in recovery of the mental nerve after surgery.

Adult↗
PubMed1991

Iontophoretic delivery of amino acids and amino acid derivatives across the skin in vitro.

The effects of penetrant properties (lipophilicity and charge) and of vehicle pH on the iontophoretically enhanced delivery of amino acids and their N-acetylated derivatives have been examined in vitro. The penetrants were nine amino acids (five were zwitterionic, two positively charged, and two negatively charged) and four N-acetylated amino acids, which carry a net negative charge at pH 7.4. Iontophoresis at constant current (0.36 mA/cm2), using Ag/AgCl electrodes, was conducted across freshly excised hairless mouse skin. Iontophoretic flux of the zwitterions was significantly greater than passive transport. Delivery from the anode was greater than from the cathode for all zwitterions. The level of enhancement was inversely proportional to permeant octanol/pH 7.4 buffer distribution coefficient. Cathodal iontophoresis of the negatively charged amino acids and of the N-acetylated derivatives produced degrees of enhancement which were significantly greater than those measured for the "neutral" zwitterions. Furthermore, the enhanced flux reached a steady-state level within a few hours for the negatively charged species, whereas the transport of the zwitterions continued to increase with time. Anodal iontophoresis of histidine and lysine, the two positively charged amino acids studied, induced substantial enhancement which was sensitive to the pH of the delivery vehicle. For example, the flux of histidine from an applied solution at pH 4 (where the amino acid carries a net positive charge) was significantly greater than that from a vehicle at pH 7.4 (where histidine is essentially neutral). The behavior of lysine was more complex and suggested a certain degree of neutralization of the skin's net negative charge.

Administration, Cutaneous↗
PubMed1991

The carcinostatic effects of 1-(2-tetrahydrofuryl)-5-fluorouracil and uracil (UFT) on tongue carcinoma induced by 4-nitroquinoline 1-oxide (4NQO) in rats.

UFT is a carcinostatic agent used in adjuvant chemotherapy for head and neck cancer. In the present study. UFT was given orally to treat tongue carcinoma in rats induced by 4-nitroquinoline 1-oxide. The antitumor effects of UFT were studied macroscopically and histologically. In addition, the antitumor effects of UFT were evaluated in relationship to lesions of the clinical and, invasive types, and to there vascular structure. In clinical lesions, the antitumor effect of UFT was higher in extrovert tumor-mass lesions and lower in ulcerous lesions. With regard to vascular structure, the effect was higher in cases demonstrating irregular net-like patterns and branch-like patterns and lower in cases in which the pattern had been destroyed. There was a correlation between antitumor effect and invasive type. As invasive tendency the 3H-thymidine labeling index, and mitotic index increased, antitumor effect and degree of tumor cell degeneration decreased.

4-Nitroquinoline-1-oxide↗
PubMed1986

Histogenesis of acinic cell carcinoma of the major and minor salivary glands. An ultrastructural study.

This study describes the light microscopic, histochemical and electron-microscopic findings of 10 acinic cell carcinomas from the major and minor salivary glands. Ultrastructurally, four cell types were identified: secretory acinar cells, intercalated duct-like cells, pluripotential reserve/stem cells and myoepithelial cells. This cellular composition suggests that the tumours are derived from neoplastic proliferation, cytodifferentiation and functional maturation of pluripotential reserve/stem cells which normally reside at the acinar-intercalated duct junctions and/or in the intercalated ducts proper of adult salivary glands. This study further supports the concept that different salivary gland tumours recapitulate various developmental stages in the normal embryogenesis of the salivary glands.

Aged↗