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H Fujitsuka

Publications and source records attributed to H Fujitsuka.

7 recordsLinked to original sources
PubMed2001

Time-resolved EPR, fluorescence, and transient absorption studies on phthalocyaninatosilicon covalently linked to one or two TEMPO radicals.

The photophysical properties of tetra-tert-butylphthalocyaninatosilicon (SiPc) covalently linked to one or two 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) radicals (R1, R2) have been studied by fluorescence, transient absorption, and time-resolved electron paramagnetic resonance (TREPR) spectroscopies. It is found that the fluorescence quantum yields and lifetimes of R1 and R2 decrease compared with those of (dihydroxy)SiPc ((dihydroxy)SiPc = 6.8 ns, R1 = 4.7 ns and 42 ps, and R2 = 4.7 ns and <30 ps). Transient absorption measurements indicate that the lifetime of the excited triplet SiPc is markedly dependent on the number of linking TEMPO radicals ((dihydroxy)SiPc = 500 micros, R1 = 7.6 micros, and R2 = 3.7 micros). These short lifetimes of R1 and R2 in the excited states are explained as a result of the interaction with TEMPO changing the ISC between the singlet and triplet states to spin-allowed transitions. Quantitative TREPR investigations have been carried out for the radical-quartet pair mechanism of R1 and the photoinduced population transfer of R2. It is determined that the rise and decay times of these electron spin polarizations denote the spin-lattice relaxation time of the ground state and the lifetime of the excited multiplet state, respectively. This study contributes not only to an elucidation of radical-chromophore interactions but also to a novel approach for controlling magnetic properties by photoexcitation.

Journal Article↗
PubMed2001

Analysis of genetic alterations in salivary gland tumors by comparative genomic hybridization.

In order to define and map chromosomal copy number alterations in salivary gland tumors (SGTs), a comparative genomic hybridization (CGH) technique was applied to two pleomorphic adenomas (PAs), one adenoid cystic carcinoma (ACC), and one basal cell adenocarcinoma (BCAC). The PAs exhibited regional copy number losses at 5q12.4-q14.1, 9q12-q21.13, and 16q11.2, as well as a gain at 20p12.1; among these, the losses at the 9q12-q21.11 and 16q11.2 regions were common to both PAs. The ACC showed overrepresentations of the entire regions of chromosomes 16 and 20, a regional gain at 22q12.3-q13.1, and no losses. In the BCAC, regional gains at 9p21.1-pter, 18q21.1-q22.3, and 22q11.23-q13.31 as well as losses at 2q24.2 and 4q25-q27 were seen; the gain at 22q12.3-q13.1 was common in both the ACC and the BCAC. These CGH data indicate that different genetic alterations are present in the different types of SGTs, and that the alterations involve several chromosomes. The discovery of common alterations in the same and/or different types of tumors might be important in the understanding of the development and progression of the SGTs.

Adenoma, Pleomorphic↗
PubMed2000

[Clinical effects of adjuvant therapy using Z-100 (Ancer 20 injection) for oral cancer--prevention of stomatitis and hematopoietic impairment].

A combination of radiotherapy and chemotherapy is a usual treatment method for malignant head and neck tumors, however chemoradiotherapy is associated with hematopoietic impairment and serious stomatitis in patients. The clinical effects and evaluation of hematopoietic activity (e.g., leukocyte count) and the degree of stomatitis under adjuvant therapy using Z-100 (Ancer 20 injection) for oral cancer were investigated for preoperative cancer therapy. In order to evaluate the clinical effects of Ancer 20 injection with regard to hematopoietic activity and the degree of stomatitis, a clinical study was performed for 18 patients with oral cancer in our department. The 18 patients, who had oral squamous cell carcinomas (5 of the tongue, 4 of the mandibular gingiva, 3 of the maxillary gingiva, 1 of the floor of the mouth, 3 of the buccal mucosa, and 2 others), were treated with this combination of adjuvant therapy with Ancer 20 injection, from March, 1991 to March, 1997. They were injected with Ancer 20 (twice a week, 40 micrograms) during the cancer treatment period. We investigated hematopoietic activity, (e.g., leukocyte and platelet counts) and the degree of stomatitis periodically, before and after the combined radiotherapy and chemotherapy treatment period. It was found that in the patients who were treated with Ancer 20 injection, the decrease in leukocyte and platelet counts was prevented and the condition of stomatitis was improved. These results suggest that Ancer 20 injection may generally improve various dysfunctions due to hematopoietic impairment by radiotherapy combined with chemotherapy, and improve immunological factors. We conclude that Ancer 20 injection is a useful adjuvant treatment for oral cancer.

Antineoplastic Agents↗
PubMed1996

Chemoprevention of 4-nitroquinoline 1-oxide-induced rat oral carcinogenesis by the dietary flavonoids chalcone, 2-hydroxychalcone, and quercetin.

The modifying effects of dietary exposure of three flavonoids, chalcone, 2-hydroxychalcone, and quercetin, during the initiation and postinitiation phases of oral tumorigenesis initiated with 4-nitroquinoline-1-oxide (4-NQO) were investigated in male F344 rats. At 6 weeks of age, animals were divided into experimental and control groups. At 7 weeks of age, all animals except those treated with test chemicals alone and the untreated control group were given 4-NQO [20 parts/million (ppm)] in the drinking water for 8 weeks to induce oral neoplasms. For chemopreventive study by feeding of test compounds during the initiation phase, groups of animals were given diets containing 500 ppm chalcone, 500 ppm 2-hydroxychalcone, or 500 ppm quercetin for 10 weeks, starting 1 week before 4-NQO exposure. Seven days after stopping 4-NQO exposure, these groups were switched to the basal diet and kept on this diet until the end of the experiment. For chemopreventive study by treatment with test chemicals during the postinitiation phase, starting 1 week after the cessation of 4-NQO administration, the groups given 4-NQO and the basal diet were switched to the diets mixed with test chemicals and maintained on these diets for 22 weeks. The other groups consisted of rats fed diets containing 500 ppm test chemicals alone or of untreated rats. Thirty-two weeks after the start of the study, the incidence of tongue neoplasms and preneoplastic lesions, polyamine levels in the tongue epithelium, and cell proliferation activity estimated by bromodeoxyuridine labeling index were compared among the different dietary groups. Feeding of all test chemicals during either initiation or postinitiation phases caused a significant reduction in the frequency of tongue carcinoma (68-88% reduction; P < 0.05). Dietary administration of these test chemicals also significantly decreased the bromodeoxyuridine labeling index of the tongue squamous epithelium (P < 0.05). In addition, polyamine levels in the oral mucosa were lowered in rats treated with 4-NQO and test chemicals when compared to those given 4-NQO alone. These results indicate that the flavonoids chalcone, 2-hydroxychalcone, and quercetin present in our daily foods have an inhibitory effect on oral carcinogenesis initiated with 4-NQO, and such a modifying effect may be related partly to the suppression of cell proliferation.

4-Nitroquinoline-1-oxide↗
PubMed1991

Intermaxillary fixation using screws. Report of a technique.

A technique of intermaxillary fixation using screws anchored in the maxilla and mandible has been described. AO (Synthes) screws with a diameter of 3.5 mm and 12 mm to 16 mm in length were inserted at the antero-lateral surface of the maxilla and the buccal surface of the mandible. This technique is particularly suitable for mandibular fractures in denture wearing patients.

Aged↗
PubMed1991

Malignant mixed tumor (malignant ameloblastoma and fibrosarcoma) of the maxilla.

We present a rare case of carcinosarcoma (malignant ameloblastoma and fibrosarcoma) of the left maxilla that developed in a 63-year-old Japanese man. The tumor recurred repeatedly despite multiple surgical removals, radiotherapy, and chemotherapy and led to progressive cachexia; the patient died after 3.8 years of hospitalization. Histopathologic examination revealed that the recurrent tumor was carcinosarcoma, which had progressed from malignant ameloblastoma with fibroma. An autopsy confirmed the diagnosis of malignant mixed tumor with lung metastasis of malignant ameloblastoma and fibrosarcoma.

Ameloblastoma↗