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Biomedical subjects

S Fujimura

Publications and source records attributed to S Fujimura.

At least 109 records · Page 6Linked to original sources

Comparative properties of envelope-associated arginine-gingipains and lysine-gingipain of Porphyromonas gingivalis.

Two arginine specific proteinases (Arg-gingipain [RGP-A, RGP-B]) and a lysine specific proteinase (Lys-gingipain [KGP]) were purified from materials of the envelope of Porphyromonas gingivalis solubilized by a detergent by the sequential procedures of ion-exchange chromatography, affinity chromatography, and isoelectric focusing. Each purified enzyme showed a single stained band on SDS-PAGE. The three enzymes were commonly activated by reducing reagents such as mercaptoethanol, dithiothreitol and cysteine. RGP-B was activated markedly by glycyl-glycine and KGP was activated significantly by EDTA. Both RGP-A and RGP-B were inhibited by p-hydroxymercuribenzoate, tosyl-L-lysine chloromethyl ketone (TLCK), N-ethylmaleimide, EDTA, leupeptin, L-trans-epoxy-succinylleucylamido-(4-guanidino)butane and antipain. KGP was inhibited by p-hydroxymercuribenzoate, N-ethylmaleimide and TLCK. The molecular masses of RGP-A and RGP-B were the same (43 kDa), and that of KGP was 48 kDa. The hydrolytic activities of RGPs and KGP to chromogenic synthetic substrates were limited to the compounds with arginine and lysine in the P-1 positions, respectively. When IgG was treated with the three enzymes separately, it was demonstrated that two new fragments of 34 kDa and 15 kDa were generated in each reaction product. Hemoglobin was almost exhaustively digested by RGP-B, but substantial degradation could not be induced by RGP-A or KGP treatment.

Adhesins, Bacterial↗

Involvement of insulin-like growth factor I in development of ossification of the posterior longitudinal ligament of the spine.

In order to investigate the pathogenesis of ossification of the posterior longitudinal ligament (OPLL) of the spine, we examined the distribution of insulin-like growth factor I (IGF-I) in the posterior longitudinal ligaments of OPLL patients, and analyzed the effects of IGF-I on the cultured spinal ligament cells. For that purpose we established eight varieties of OPLL and non-OPLL cell lines obtained from spinal ligaments of corresponding patients, respectively. In contrast to non-OPLL cases, all the OPLL cases were histologically shown to contain round-shaped cartilage-like cells in the transitional region from preossifying to ossifying ligaments, and these cells were strongly stained with an antibody for IGF-I. In the vicinity of preossifying cartilaginous tissues, ligament cells also had a rod-like appearance and were positive for IGF-I immunohistochemically. The effects of IGF-I on cultured spinal ligament cells were assayed by alkaline phosphatase (AP) activity, DNA synthesis, and the amounts of collagen produced. The number of OPLL cell lines that increased AP activity, responding to IGF-I irrespective of 1,25(OH)2D3, was significantly larger than that of non-OPLL cell lines, although IGF-I stimulated DNA and procollagen type I carboxyl-terminal peptide synthesis in most of both OPLL and non-OPLL cell lines. These data demonstrate the dominant expression of IGF-I in the posterior longitudinal ligaments of OPLL patients, and suggest that IGF-I preferentially induces osteogenic differentiation in OPLL cells rather than in non-OPLL cells. IGF-I, therefore, may be involved in the local ossification process of spinal ligaments observed in OPLL patients.

Adult↗

The H-cadherin (CDH13) gene is inactivated in human lung cancer.

We have previously reported frequent allelic loss in chromosome bands 16q24.1-q24.2 in human lung cancer. Since the H-cadherin (CDH13) gene has been isolated and mapped to this common region of allelic loss, we have investigated this gene in human lung cancer. The reverse transcription/polymerase chain reaction technique has revealed the loss of expression in four (57%) of seven lung cancer cell lines. To study the CDH13 gene further, we have analyzed deletions, genetic alterations, and methylation status at the 5' region of this gene. Three (75%) of four cell lines that have lost expression show a deletion of the CDH13 locus accompanied by hypermethylation of the remaining allele. Moreover, hypermethylation has been observed in nine (45%) of 20 primary lung cancers. These results suggest that a combination of deletion and hypermethylation causes inactivation of the CDH13 gene in a considerable number of human lung cancers.

Base Sequence↗

Prognostic assessment of 1310 patients with non-small-cell lung cancer who underwent complete resection from 1980 to 1993.

OBJECTIVE: The TNM staging system of lung cancer is widely used as a guide for estimating prognosis and selecting treatment modality. In 1997, the International Union Against Cancer and the American Joint Committee on Cancer have adopted a revised stage grouping for lung cancer. However, the validity of the new stage grouping has not been fully established. We investigated the prognoses of patients who had resection of non-small-cell lung cancer to confirm the validity of the revised classification. METHODS: A total of 1310 patients with non-small-cell lung cancer underwent complete resection and pathologic staging of the disease in our hospitals from 1980 through 1993. A pulmonary resection was performed with a systematic nodal dissection. The survivals were calculated with the Kaplan-Meier method on the basis of overall deaths, and the survival curves were compared by log rank test. RESULTS: There were significant differences in survival between patients with T1 N0 M0 and T2 N0 M0 disease and between those with T1 N1 M0 and T2 N1 M0 disease. However, there was no significant difference between patients with T2 NO M0 disease and those with T1 N1 M0 disease. No significant difference in survival was observed among patients with T2 N1 M0, T3 NO M0, and T3 N1 M0 cancer. Patients with different invaded organs of T3 subdivision (pleura, chest wall, pericardium, or diaphragm) had a different prognosis. There was no significant difference between patients with T3 N2 M0 disease and those with stage IIIB disease. CONCLUSIONS: We supported most of the revision, such as dividing stage I, dividing stage II, and putting T3 N0 M0 to stage IIB. Furthermore, we found some candidates for a subsequent revision, such as putting T3 N1 M0 to stage IIB, putting T2 N0 M0 and T1 N1 M0 together, regarding diaphragm invasion as T4, and putting T3 N2 M0 to stage IIIB.

Carcinoma, Non-Small-Cell Lung↗

Retinoic acids induce growth inhibition and apoptosis in adult T-cell leukemia (ATL) cell lines.

Adult T-cell leukemia (ATL) is a peripheral T-cell neoplasm caused by human T-cell leukemia virus type I (HTLV-I). Despite the administration of combined intensive chemotherapy, the reported survival time of patients with acute and lymphoma types of ATL is less than 10 months. We therefore examine the effects of all-trans-retinoic acid (ATRA), 9-cis-RA and 13-cis-RA and tried to elucidate the mechanisms of inducing growth inhibition and apoptosis by these RAs using four ATL cell lines established in our laboratory. All the investigated RAs inhibited cell growth and the cells were arrested at the G1 phase. Apoptosis was induced in three out of four cell lines. Among the growth regulatory proteins examined, the level of p21Waf1/Cip1 protein was found to increase after RA treatment, thus resulting in pRb hypophosphorylation which also induced the arrest of the cells at the G1 phase. In addition, the p53 level decreased at the same time. Fas-FasL system and the downregulation of CD25 (IL-2R/alpha) expression did not seem to be involved. Based on these findings, the ability of RAs to induce a remission of ATL is thus strongly suggested.

Adult↗

Occult lung cancer beyond bronchoscopic visibility in sputum-cytology positive patients.

Sputum cytology is useful for screening and diagnosis of centrally located lung cancer in Japan. On the other hand, cancer beyond the range of bronchoscopic visibility in X-ray negative patients can be detected only with difficulty. Of 265 patients detected by sputum cytology in mass screening, 85 had an abnormal chest roentgenogram and the remaining 180 were roentgenographically occult. A total of 200 roentgenographically occult squamous cell carcinoma lesions were detected in the above 180 patients. A total of 45 of the 200 lesions were bronchoscopically occult. Twenty-two of the above 45 lesions were beyond the range of bronchoscopic visibility with a standard bronchoscope. The data obtained show that a sputum cytology positive, X-ray negative squamous cell carcinoma may lie outside the reach of a flexible bronchoscope. Thus, when it is difficult to localize a cancer, brushing of the peripheral bronchi beyond bronchoscopic visibility and chest computed tomography should be performed.

Adult↗

What kind of hilar lung cancer can be a candidate for segmentectomy with curative intent?: Retrospective clinicopathological study of completely resected roentgenographically occult bronchogenic squamous cell carcinoma.

Although a randomized control trial demonstrated that limited surgery for small peripheral lung cancers was not as curative as lobectomy, there have been no reports concerning segmentectomy for small hilar lung cancers. In this study, we analyzed the clinicopathological features of roentgenographically occult bronchogenic squamous cell carcinomas in order to select candidates for limited resection with curative intent. From April 1982 through June 1995, 105 roentgenographically occult bronchogenic squamous cell carcinomas whose proximal edge of the lesion was more peripheral than the orifice of the segmental bronchus were completely resected. The bronchoscopic findings of the lesions were classified into three categories: remarkable, minute and hidden. Moreover, in terms of the range of endoscopic visibility, the lesions were classified into two categories: lesions within the range of endoscopic visibility and those beyond it. If lymph nodes show no signs of metastasis, roentgenographically occult bronchogenic squamous cell carcinoma is regarded as localized carcinoma and can be a candidate for segmentectomy with curative intent. In cases with minute or hidden bronchoscopic findings or of lesions within the range of endoscopic visibility, metastatic lymph nodes were never observed. Accordingly, roentgenographically occult bronchogenic squamous cell carcinomas with minute or hidden bronchoscopic findings or those within the range of endoscopic visibility can be candidates for curative segmentectomy.

Bronchoscopy↗

K-ras point mutation occurs in the early stage of carcinogenesis in lung cancer.

In order to determine the topographical distribution of the K-ras codon 12 mutations in carcinoma and preneoplastic lesions of the lung, selective ultraviolet radiation fractionation, as well as microdissection followed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RELP), was performed. Fourteen of 61 samples amplified (23.0%) had a mutation in the K-ras codon 12. Of 41 adenocarcinoma, 12 samples (29.3%) had a mutation, whereas none of the squamous cell carcinomas had a mutation. One of six large-cell carcinomas, one of three carcinoid tumours and none of three other carcinomas had a mutation. Direct sequencing revealed that K-ras codon 12 of six samples were TGT (Cys), five samples were GTT (Val), two samples were GCT (Ala) and one sample was TTT (Phe). A total of 113 lesions of 13 cases covered by dot were amplified after UV radiation. All of 74 carcinoma lesions had the mutation, and intratumour heterogeneity was not observed. Of 39 non-malignant lesions, one type II cell hyperplasia had the mutation, which suggests that the K-ras mutation occurs in the early stage of carcinogenesis. The lack of intratumour heterogeneity supports the hypothesis.

Adenocarcinoma↗

Sequential loss of heterozygosity in the progression of squamous cell carcinoma of the lung.

Radiographically occult bronchogenic squamous cell carcinomas are early lung cancers that localize mainly in the bronchial wall, and are thought to be a good model for investigating genetic alterations through lung cancer progression. In order to elucidate sequential genetic changes in lung cancers, we analysed the incidence of allelic losses on chromosome regions 2q33, 3p21, 5q21, 7q31, 9p21 and 17p13 for 40 cases of radiographically occult bronchogenic squamous-cell carcinomas and 40 cases of advanced lung cancers microdissected. In this study we used eight microsatellite dinucleotide polymorphic markers. Frequent loss of heterozygosity (LOH) was observed on 3p21 (53%), 5q21 (44%) and 17p13 (61%) in roentgenographically occult bronchogenic squamous cell carcinomas. 2q, 7q and 9p were lost less frequently in both roentgenographically occult bronchogenic squamous cell carcinomas and advanced lung cancers. These results suggest that several tumour-suppressor genes are associated with lung cancer progression and that genetic changes on 3p21, 5q21 and 17p13 are early events.

Carcinoma, Bronchogenic↗

Haemoglobin receptor protein is intragenically encoded by the cysteine proteinase-encoding genes and the haemagglutinin-encoding gene of Porphyromonas gingivalis.

The obligately anaerobic bacterium Porphyromonas gingivalis produces characteristic black-pigmented colonies on blood agar. It is thought that the black pigmentation is caused by haem accumulation and is related to virulence of the microorganism. P. gingivalis cells expressed a prominent 19 kDa protein when grown on blood agar plates. Analysis of its N-terminal amino acid sequence indicated that the 19 kDa protein was encoded by an internal region (HGP15 domain) of an arginine-specific cysteine proteinase (Arg-gingipain, RGP)-encoding gene (rgp1) and was also present in genes for lysine-specific cysteine proteinases (prtP and kgp) and a haemagglutinin (hagA) of P. gingivalis. The HGP15 domain protein was purified from an HGP15-overproducing Escherichia coli and was found to have the ability to bind to haemoglobin in a pH-dependent manner. The anti-HGP15 antiserum reacted with the 19 kDa haemoglobin-binding protein in the envelope of P. gingivalis. P. gingivalis wild-type strain showed pH-dependent haemoglobin adsorption, whereas its non-pigmented mutants that produced no HGP15-related proteins showed deficiency in haemoglobin adsorption. These results strongly indicate a close relationship among HGP15 production, haemoglobin adsorption and haem accumulation of P. gingivalis.

Amino Acid Sequence↗

Characterization of gyrA, gyrB, grlA and grlB mutations in fluoroquinolone-resistant clinical isolates of Staphylococcus aureus.

The distribution of fluoroquinolone resistance-associated point mutations in genes encoding the subunits of DNA gyrase and DNA topoisomerase i.v. was examined in 110 clinical isolates of Staphylococcus aureus. Point mutations were detected by polymerase chain reaction (PCR) and restriction fragment length polymorphism analysis and mutations were further characterized by sequencing of PCR products. Mutations at Ser84 of GyrA were widely distributed among isolates exhibiting various degrees of fluoroquinolone resistance, and border zones between mutant and non-mutant strains based on drug susceptibility were generally distinct. Mutations at Ser80 of GrlA were also widely distributed, but border zones between mutant and non-mutant isolates were in this case less distinct and several GrlA mutants were highly susceptible to sparfloxacin and tosufloxacin. Only two gyrB mutants and one grlB mutant were observed among the isolates: all contained a previously unreported mutation. GyrA and grlA mutations thus appear to impart high levels of fluoroquinolone resistance in many S. aureus clinical isolates.

Anti-Infective Agents↗

Threonine requirements of laying hens.

In order to determine the Thr requirement of laying hens, two experiments were conducted using laying performance and plasma Thr concentration as parameters. At 29 and 39 wk of age, 100 and 600 laying hens in Experiments 1 and 2, respectively, with average BW and high egg production rate, were randomized, housed in individual cages, and given free access to water and experimental diets with five graded levels of Thr: 0.31, 0.39, 0.46, 0.54, and 0.61% for 21 d in Experiment 1 and diets with 0.31, 0.36, 0.41, 0.46 and 0.51% Thr for 58 d in Experiment 2. On the last day of the experiment, blood samples were taken for determination of plasma amino acid concentration. Feed intake and daily egg mass increased and then decreased linearly as dietary Thr increased. Plasma Thr increased slowly, then sharply with increasing dietary Thr levels. Using the broken-line model, the Thr requirements were estimated to be 0.425, 0.428, and 0.430% or 453, 456, and 458 mg/hen per d in Experiment 1 and 0.395, 0.404, and 0.400%, or 457, 467, and 462 mg/hen per d, in Experiment 2, for egg mass, feed efficiency, and plasma Thr concentration, respectively. These results indicate that the Thr requirements expressed as milligrams per hen per day as determined by plasma Thr concentration agree with those of laying performance.

Aging↗

Clotrimazole, an imidazole antimycotic, is a potent inhibitor of angiogenesis.

Clotrimazole, an imidazole antimycotic, interferes with the rise in cytosolic Ca2+ and inhibits cell proliferation in a reversible manner. Here we describe the effect of clotrimazole on vascular endothelial cells (ECs). Clotrimazole inhibited the proliferation of ECs stimulated with typical angiogenic growth factors; vascular endothelial growth factor and basic fibroblast growth factor (bFGF). This inhibitory effect of clotrimazole was dose-dependent and the maximal inhibition was observed at a concentration of 10 mM. We did not observe any increase in 51Cr release from ECs during treatment with 10 microM clotrimazole. Moreover, clotrimazole inhibited the basal and bFGF-stimulated migration of ECs. As clotrimazole inhibited two principle components of angiogenesis; the proliferation and migration of ECs, we examined whether clotrimazole inhibited angiogenesis. Tube formation by ECs in type 1 collagen gel was investigated, and clotrimazole was found to be significantly inhibitory. The inhibitory effect of clotrimazole on angiogenesis was further confirmed in an in vivo angiogenesis model of murine Matrigel plug assay. These results demonstrate that clotrimazole is a potent inhibitor of angiogenesis.

Animals↗