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Biomedical subjects

K Sekine

Publications and source records attributed to K Sekine.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Antiangiogenic and antimetastatic effects of toremifene citrate].

In this study, we demonstrated that toremifene citrate (TOR) inhibited the tube formation and migration of human umbilical vein endothelial cells (HUVEC) in vitro. Moreover, TOR suppressed angiogenesis in rabbit cornea and lung metastasis of human fibrosarcoma HT-1080 cells in nude mice. The antiangiogenic activity in vitro was apparent at the concentration of 5 microM which is clinically achievable by oral administration of 120 mg/kg of TOR. These results suggest that clinical treatment with 120 mg/day of TOR might be expected to exhibit antiangiogenesis and antimetastasis effects, in addition to inhibition of estrogen-dependent tumor cell growth.

Angiogenesis Inhibitors↗
PubMed2000

FGF10 acts as a major ligand for FGF receptor 2 IIIb in mouse multi-organ development.

FGF receptor 2 isoform IIIb (FGFR2b), originally discovered as a receptor for FGF7, is known to be an important receptor in vertebrate morphogenesis, because FGFR2b null mice exhibit agenesis or dysgenesis of various organs, which undergo budding and branching morphogenesis. Since FGF7 null mice do not exhibit marked defects in organogenesis, it has been considered that other FGF(s) than FGF7 might function as a major ligand for FGFR2b during organogenesis. One of the candidate ligands is FGF10, because FGF10 binds to FGFR2b with high affinity and the formation of the limb and lung is arrested in FGF10 null mice as found in FGFR2b-deficient mice. Previous analyses of FGF10 null mice revealed that FGF10 is required for limb and lung development. To elucidate the role of FGF10 in wide-range organogenesis, we further analyzed the phenotypes of the FGF10 knockout mice. We found diverse phenotypes closely related to those for FGFR2b-deficient mice, which includes the absence of thyroid, pituitary, and salivary glands, while minor defects were observed in the formation of teeth, kidneys, hair follicles, and digestive organs. These results suggest that FGF10 acts as a major ligand for FGFR2b in mouse multi-organ development.

Animals↗
PubMed2000

Analysis of the p16INK4, p14ARF, p15, TP53, and MDM2 genes and their prognostic implications in osteosarcoma and Ewing sarcoma.

We examined alterations of the p16INK4, p14ARF, p15, TP53, and MDM2 genes in 30 osteosarcomas and 24 Ewing sarcomas. Among 21 osteosarcomas and 24 Ewing sarcomas, p16INK4, p14ARF, and p15 abnormalities were found in 4 (19%), 2 (9%), and 3 (14%) osteosarcomas, respectively, and in 4 (17%), 3 (13%), and 4 (17%) Ewing sarcomas, respectively. The alterations of p16INK4, p14ARF, and p15 included homozygous deletions spanning all 3 genes, methylation of p16INK4 or p15, and a nonsense mutation of p16INK4, which simultaneously caused a missense mutation of p14ARF. Alterations of TP53 were found in 15 (50%) of 30 osteosarcomas and 1 (3%) of 24 Ewing sarcomas. None of the sarcomas showed MDM2 amplification. While TP53 abnormalities were far more frequent in osteosarcoma than in Ewing sarcoma, alterations of p16INK4, p14ARF, and p15 were present at similar frequencies in the two types of sarcoma. The event-free survival (EFS) was worse in Ewing sarcoma patients with p16INK4 and p14ARF mutation/deletion than in those without the mutation/deletion (P = 0.019), and EFS was worse in osteosarcoma patients with TP53 alterations than in those without TP53 alterations (P = 0.048). The different incidence of TP53 abnormalities in the 2 types of sarcoma may reflect differences of the molecular processes through which the 2 types of tumor develop.

Adolescent↗
PubMed2000

Prevention of colon carcinogenesis and carcinoma metastasis by orally administered bovine lactoferrin in animals.

Bovine lactoferrin (bLF), a milk protein known to have bacteriostatic properties was examined for its preventive effects on colon and other organ carcinogenesis and experimental metastasis. (Experiment 1) The influence on colon carcinogenesis was investigated in male rats treated with azoxymethane (AOM), then received 2 or 0.2% bLF for 36 weeks. Significant reduction in the incidence (27% and 46% of the control, respectively) and number of adenocarcinomas of the large intestine was observed. (Experiment 2) In BALB/c mice bearing subcutaneous (s.c.) implants of colon carcinoma 26 (Co 26Lu). bLF demonstrated significant inhibition of spontaneous lung metastasis (approximately 43% of the control). Number of cytotoxic asialoGM1+ and CD8+ cells in white blood cells increased (171% and 122% of control, respectively) after treatment. Results of those experiments indicate that bLF remarkably prevents colon carcinogenesis and lung metastasis of colon carcinoma cells, possibly due to increasing cytotoxic cells in the peripheral blood.

Animals↗
PubMed2000

Phase I/II study of cisplatin, ifosfamide and irinotecan with rhG-CSF support in patients with stage IIIB and IV non-small-cell lung cancer.

PURPOSE: We conducted a phase I/II study in previously untreated patients with stage IIIB or IV non-small-cell lung cancer (NSCLC) to: (1) determine the maximum tolerated dose (MTD) of cisplatin combined with a fixed schedule of ifosfamide and irinotecan with rhG-CSF support; and (2) to determine the overall response rate and median survival of patients entered on this study. METHODS: Ifosfamide (1.5 g/m2) and irinotecan (60 mg/m2) were administered at fixed doses on days 1-4 and on days 1, 8 and 15, respectively. Cisplatin was given on day 1 at 60 mg/m2 and was increased in 10-mg/m2 increments. This regimen was repeated every 4 weeks. rhG-CSF (nartograstim) was administered subcutaneously at a dose of 1 microg/kg on days 5-18 except on the day of irinotecan treatment. RESULTS: Between June 1995 and April 1998, 46 patients were registered onto this phase I/II study. The MTD of cisplatin was defined according to toxicity and the dose during three courses was increased. Since at the 80 mg/m2 dose level more than one-third of the patients were treated with dose modification, the dose of 70 mg/m2 was recommended for phase II study. The dose-limiting toxicity was leukopenia. The overall response rate was 62.2% (95% CI 48.0-76.4%, the median response duration was 144 days, and the median survival time was 393 days. CONCLUSION: For phase II study, we recommend doses of cisplatin 70 mg/m2 on day 1 combined with ifosfamide and irinotecan with rhG-CSF support. Both the response rate and preliminary survival data in this study suggest a high degree of activity of this combination in previously untreated NSCLC.

Adult↗
PubMed2000

Application of boundary element method to calculation of the complex permittivity of suspensions of cells in shape of Dinfinityh symmetry.

A numerical method using the boundary element method was developed to calculate the complex permittivity of suspensions of particles in the shape of Dinfinityh symmetry covered with a shell phase. It was an extension of the analytical methods based on Maxwell-Wagner-Sillars' effects in suspensions of shelled ellipsoids. This method was applied to particles, which were relevant to budding yeast cells and erythrocytes, to examine the effects of the shape on frequency-dependence of the permittivity and conductivity of their suspensions. Results of the calculations showed that the permittivity and conductivity at high frequencies were insensitive to the change in the shape. The change in shape affected the permittivity and conductivity at low frequencies and their frequency-dependence in the intermediate frequency region. This behavior could not be imitated by the calculation using analytical methods with shelled spheroid models.

Animals↗
PubMed2000

Milk and dairy products in cancer prevention: focus on bovine lactoferrin.

Milk and dairy products constitute an important part of the western style diet. A large number of epidemiological studies have been conducted to determine effects of consumption on cancer development but the data are largely equivocal, presumably reflecting the different included components. It has been proposed that whereas fats in general could promote tumor development, individual milk fats like conjugated linoleic acid could exert inhibitory effects. There is also considerable evidence that calcium in milk products protects against colon cancer, while promoting in the prostate through suppression of circulating levels of 1,25-dihydroxyvitamin D3. Whey protein may also be beneficial, as shown by both animal and human studies, and experimental data have demonstrated that the major component bovine lactoferrin (bLF), inhibits colon carcinogenesis in the post-initiation stage in male F344 rats treated with azoxymethane (AOM) without any overt toxicity. The incidence of adenocarcinomas in the groups receiving 2% and 0.2% bLF were thus 15% and 25%, respectively, in contrast to the 57.5% control value (P<0.01 and P<0.05, respectively). Results in other animal models have provided further indications that bLF might find application as a natural ingredient of milk with potential for chemoprevention of colon and other cancers.

Adenocarcinoma↗
PubMed2000

Isoflavonoids from Pueraria mirifica and their estrogenic activity.

Nine isoflavonoids including a new pterocarpene, puemiricarpene, were isolated from the tuberous root of Pueraria mirifica (Leguminosae). The structure of puemiricarpene was determined by spectroscopic means. Estrogenic activity of the isolated isoflavonoids was tested using MCF-7 human breast cancer cells. Moderate activity was observed for kwakhurin, a prenylated isoflavonoid.

Estrogens, Non-Steroidal↗
PubMed2000

Phase I study of carboplatin, docetaxel and irinotecan with recombinant human granulocyte colony stimulating factor support in patients with advanced non-small cell lung cancer.

A phase I study was conducted in patients with stage IIIB or IV non-small cell lung cancer to determine the maximum tolerated dose (MTD) of irinotecan combined with a fixed schedule of docetaxel and carboplatin with recombinant human granulocyte colony stimulating factor (rhG-CSF) (nartograstim) support. Docetaxel was given at 60 mg/m2 on day 1 with carboplatin. The dose of carboplatin was calculated using the Calvert formula to achieve an estimated AUC of 5.0 mg/ml x min. Irinotecan was administered at a starting dose of 40 mg/m2 on day 1 and increased in increments of 10 mg/m2. rhG-CSF was given at 1 microg/kg on days 5-15. Cycles were repeated every 3 weeks. Between February 1998 and March 1999, 22 patients were enrolled in this phase I study. Five patients were chemotherapy naive. The MTD of irinotecan was 60 mg/m2. Diarrhea was considered to be the dose-limiting toxicity. The irinotecan dose intensity of 16.7 mg/m2/week was low compared with other irinotecan-containing regimens. The overall response rate was 38.1% and median survival was 278 days. Irinotecan 50 mg/m2 in combination with 60 mg/m2 docetaxel and carboplatin on day 1 with rhG-CSF support is recommended for phase II study. The response rate and survival data in this phase I study are encouraging.

Adult↗
PubMed2000

Activation of intestinal mucosal immunity in tumor-bearing mice by lactoferrin.

We have previously demonstrated that oral administration of bovine lactoferrin (bLF) markedly increases CD4(+) and CD8(+) T cells and NK (asialoGM1(+) ) cells in the blood of tumor-bearing mice and enhances anti-metastatic activity. In this paper, we document that oral administration of bLF and bLF-hydrolysate (bLFH) is associated with strong increases in CD4(+) and CD8(+) T, as well as asialoGM1(+) cells in lymphoid tissues and lamina propria of the small intestine in mice, especially in tumor-bearing animals in which Co26Lu cells were implanted subcutaneously. Moreover, IgM(+) and IgA(+) B cells in lamina propria of the small intestine were also significantly increased by bLF and bLFH. Bovine apo-transferrin (bTF) did not exhibit such activity. In the colon, only CD8(+) cells were significantly increased by treatment with bLF, while asialoGM1(+) cells were significantly decreased. bLF and bLFH induced cytokines to activate T, B and asialoGM1(+) cells. Administration of bLF and bLFH, but not bTF, increased production of interleukin-18 (IL-18), interferon-gamma (IFN-gamma) and caspase-1 in the mucosa of the small intestine. Particularly high levels of IL-18 were found in the epithelial cells of the small intestine. Moreover, administration of bLF and bLFH, but not bTF, induced IFN-gamma presenting cells in the small intestine. Caspase-1, which processes proIL-18 to mature IL-18, was also induced in the epithelial cells of the small intestine following treatment with bLF and bLFH, but not with bTF. These results suggest that enhanced production of IL-18 and IFN-gamma and caspase-1 induction by treatment with bLF may be important for elevation of intestinal mucosal immunity.

Administration, Oral↗
PubMed2000

Chemopreventive effects of bovine lactoferrin on N-butyl-N-(4-hydroxybutyl)nitrosamine-induced rat bladder carcinogenesis.

Chemopreventive effects of bovine lactoferrin (bLF), which is found at high concentrations in colostrum, on rat bladder carcinogenesis were investigated using a rat bladder medium-term bioassay. In experiment 1, a total of 80 F344 male rats, 6 weeks old, were divided into 5 groups. Groups 1 and 2 were treated with 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) in the drinking water for 8 weeks and after a 1-week interval, received dietary supplementation with 2% and 0.2% bLF, respectively. Group 3 received 0.05% BBN for 8 weeks and then no treatment. Group 4 was administered 2% bLF alone from week 9, without prior carcinogen exposure. Group 5 was maintained without any treatment throughout the experiment. All rats were killed at the end of week 36. Group 1 demonstrated a significantly decreased multiplicity of the bladder tumors (carcinomas and papillomas) as compared with group 3. Maximum cut surface areas of bladder tumors were also significantly decreased in groups 1 and 2 compared with group 3. No bladder tumors were observed in groups 4 or 5. In experiment 2, a total of 60 rats were divided into two groups (30 rats each); both were treated with 0.05% BBN for 4 weeks and after a 1-week interval, one received 2% bLF (group 1) and the other, basal diet (group 2) for 4 weeks. Group 1 demonstrated a tendency for decrease of the 5-bromo-2'-deoxyuridine (BrdU) labeling index. bLF was detected in the urine of rats fed bLF by ELISA as well as western blot analysis. The findings indicate that 2% bLF can inhibit BBN-induced rat bladder carcinogenesis, and that this may be due to bLF in the urine.

Acetyltransferases↗
PubMed2000

Combination of cisplatin, ifosfamide, and irinotecan with rhG-CSF support for the treatment of refractory or relapsed small-cell lung cancer.

OBJECTIVE: This study was conducted in refractory or relapsed small-cell lung cancer to determine activity and toxicity of the combination of cisplatin, ifosfamide, and irinotecan with rhG-CSF support. METHODS: Eighteen patients entered the trial. The median chemotherapy-free interval was 3.1 (range 1.0-14.5) months. Cisplatin (20 mg/m(2)) and ifosfamide (1.5 g/m(2)) were administered on days 1-4, and irinotecan (60 mg/m(2)) was administered on days 1, 8, and 15. In patients who experienced grade 4 hematological toxicity during the prior chemotherapy, the doses of cisplatin and irinotecan were reduced to 15 and 50 mg/m(2), respectively. After 10 patients were entered, cisplatin and irinotecan were administered at doses of 15 and 50 mg/m(2), respectively. This regimen was repeated every 4 weeks. rhG-CSF was administered subcutaneously at a dose of 50 microgram/m(2) from days 50 to 18, except on the day of irinotecan treatment. RESULTS: All patients could be assessed for response and toxicity. There were 1 complete and 16 partial responses, and an overall response rate of 94.4%. The median survival time of all patients was 339 days, and the 1-year survival rate was 47.5%. Hematological toxicities were significant. Grade 4 neutropenia and thrombocytopenia were observed in 61 and 33% of the patients, respectively. Diarrhea was mild and transient. There was no treatment-related death. CONCLUSION: The combination of cisplatin, ifosfamide, and irinotecan with rhG-CSF support was highly active for the treatment of refractory or relapsed small-cell lung cancer.

Adult↗
PubMed2000

Combination chemotherapy of cisplatin, ifosfamide, and irinotecan with rhG-CSF support in patients with brain metastases from non-small cell lung cancer.

BACKGROUND: Brain metastases develop frequently in patients with non-small cell lung cancer (NSCLC), and the prognosis for these patients is very poor. We evaluated the role of chemotherapy for patients with brain metastases from NSCLC. METHODS: We analyzed 30 patients who were discovered to have brain metastases during the diagnosis of 121 patients enrolled in three consecutive clinical trials on advanced NSCLC assessing combination chemotherapy of cisplatin, ifosfamide and irinotecan with rhG-CSF support. Response in the brain lesions was evaluated by contrast-enhanced MRI scans after at least two courses. RESULTS: Fourteen patients achieved a partial response (PR) but there was no change (NC) in 13 patients and progressive disease (PD) in 1. Among patients with extracranial lesions, 18 had a PR and 11 had NC. The response rate in brain metastases was 50.0%, and that in extracranial primary and metastatic lesions was 62.1%. The median duration of response for intra- and extracranial lesions was 140 and 147 days, respectively. After completing chemotherapy, Gamma Knife radiosurgery was performed on 2 patients in remission and 8 patients at disease progression. The median survival time and 1-year survival rate were 382 days and 56.1%, respectively. CONCLUSIONS: Both the response rate and survival data in this retrospective study suggest a high degree of activity of this combination chemotherapy in patients with brain metastases from NSCLC.

Adult↗
PubMed2000

Orally administered lactoferrin exerts an antimetastatic effect and enhances production of IL-18 in the intestinal epithelium.

The effects of oral administration of bovine lactoferrin (bLF) and its hydrolysate on the lung colonization by colon 26 carcinoma were investigated. At doses of 100 or 300 mg/kg/day for seven successive days, bLFs demonstrated a significant inhibitory effect on experimental metastasis, which indicated effectiveness before and after tumor implantation. Oral administration of bLFs augmented CD4+, CD8+, and asialoGM1+ cells in the spleen and peripheral blood. Their cytotoxic activities against Yac-1 and colon 26 carcinoma were enhanced by bLF. In the small intestinal epithelium, CD4+ and CD8+ cells were markedly increased, and, simultaneously, enhanced production of interleukin-18 (IL-18) was confirmed in the intestinal epithelial cells. In this model, intravenous injection of murine IL-18 showed significant inhibition of the lung colonization by colon 26 carcinoma. These results suggested that inhibition of experimental metastasis by oral administration of bLF and pepsin hydrolysate of bLF might be due to enhanced cellular immunity, presumably mediated by enhanced IL-18 production in the intestinal epithelium.

Administration, Oral↗
PubMed2000

Molecular analysis of external genitalia formation: the role of fibroblast growth factor (Fgf) genes during genital tubercle formation.

The molecular mechanisms underlying the development of the external genitalia in mammals have been very little examined. Recent gene knockout studies have suggested that the developmental processes of its anlage, the genital tubercle (GT), have much in common with those of limb buds. The Fgf genes have been postulated as regulating several downstream genes during organogenesis. Fgf8 was expressed in the distal urethral plate epithelium of the genital tubercle (GT) together with other markers such as the Msx1, Fgf10, Hoxd13 and Bmp4 expressed in the mesenchyme. To analyze the role of the FGF system during GT formation, an in vitro organ culture system was utilized. It is suggested that the distal urethral plate epithelium of GT, the Fgf8-expressing region, regulates the outgrowth of GT. Ectopic application of FGF8 beads to the murine GT induced mesenchymal gene expression, and also promoted the outgrowth of the GT. Experiments utilizing anti-FGF neutralizing antibody suggested a growth-promoting role for FGF protein(s) in GT outgrowth. In contrast, despite its vital role during limb-bud formation, Fgf10 appears not to be primarily essential for initial outgrowth of GT, as extrapolated from Fgf10(-/-) GTs. However, the abnormal external genitalia development of Fgf10(-/-) perinatal mice suggested the importance of Fgf10 in the development of the glans penis and the glans clitoridis. These results suggest that the FGF system is a key element in orchestrating GT development.

Animals↗
PubMed2000

[Intrathoracic neurofibroma originating in the left vagus nerve].

A 20-year-old man was admitted because of an abnormal mass shadow on chest X-ray film. Computed tomography (CT) and magnetic resonance imaging (MRI) disclosed a mass lesion in the superior portion of the left mediastinum. CT scans showed a well-defined mass with low density. Axial MRI rendered the mass lesion with intermediate signal intensity on T1-weighted images and high signal intensity on T2-weighted images. The preoperative diagnosis was bronchogenic cyst. Video-assisted thoracic surgery revealed that the tumor originated in the truncus of the left vagus nerve. The resected tumor was 90 x 24 x 18 mm in size. The postoperative course was uneventful and hoarseness did not develop. The pathologic diagnosis was benign mediastinal neurofibroma without von Recklinghausen's disease. Such cases are extremely rare in the Japanese literature.

Adult↗
PubMed1999

Heterocyclic amine mixture carcinogenesis and its enhancement by caffeine in F344 rats.

In order to elucidate whether mixed exposure to environmental carcinogens and caffeine increases the risk of cancer induction, we investigated the relationship between preneoplastic lesion development in the liver and colon and drug metabolizing enzyme induction and DNA adduct formation, in rats treated with a mixture of heterocyclic amines (HCAs) and caffeine. In Experiment 1, male F344 rats were administered 3 different HCAs, the food carcinogens, 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), alone or in combinations of 2 or 3 at 50 ppm in the diet for 16 weeks. The numbers of hepatic glutathione-S-transferase P form positive (GST-P+) foci and colonic aberrant crypt foci (ACF) were greater in the IQ + MeIQx group than expected from simple summation and increased levels of HCA-DNA adducts were noted. However, no summation was obtained when combined with PhIP, which rather caused inhibition. In Experiment 2, the effects of concurrent caffeine administration on the PhIP carcinogenicity were assessed. Caffeine at 1000 and 500 ppm in the drinking water for 2 weeks significantly increased levels of CYP1A2. Ten weeks concurrent administration of caffeine (1000 ppm) and PhIP (400 ppm) resulted in significant increase of colon ACFs and CYP1A2 expression. Thus, concurrent administration of IQ and MeIQx caused elevation of their carcinogenicity but other mixtures with PhIP did not enhance carcinogenicity. However, a non-carcinogen, caffeine, enhanced PhIP colon carcinogenesis, possibly due to induction of CYP1A2.

Animals↗