Search PubMed⌕ Search

Biomedical subjects

J Fukuda

Publications and source records attributed to J Fukuda.

At least 19 recordsLinked to original sources
PubMed2006

Morphological features of cartilage observed during mandibular distraction in rabbits.

Ossification during distraction osteogenesis can be classified as intramembranous or endochondral. It is not known whether cartilage in the distraction gap is transformed into new bone. The aim of this study was to investigate the morphological features of ossification in the transition of cartilage to bone during mandibular distraction osteogenesis in a rabbit model. A cortical osteotomy was performed and custom-made devices were applied. Immediately after surgery, the devices were lengthened by 0.25 mm every 12h for up 10 days, during which time four rabbits were killed at 0, 5 and 10 days and examined using histological staining and immunohistochemical methods. Apoptotic cells were identified by an in-situ detection assay for nuclear DNA fragmentation using a modified TUNEL procedure, with several sections analyzed using software for histomorphometric analysis. The results showed that the amount of cartilage in the distraction gap was significantly decreased. The cartilage had ossified in two ways, termed endochondral ossification and transchondroid bone formation.

Alkaline Phosphatase↗
PubMed2006

A simple method for bone positioning of mandibular segments.

A simple bone-positioning technique is reported, using a combination of bone plates and a flexible tube filled with acrylic polymer. The flexible tube is solidified by injection of acrylic monomer. This technique is applicable for bone positioning after mandibular resection as well as positioning of the proximal segment after sagittal split ramus osteotomy. This technique has the advantages of greater simplicity and flexibility compared to previously reported methods of bone positioning.

Acrylic Resins↗
PubMed2006

Hepatocyte spheroid formation on a titanium dioxide gel surface and hepatocyte long-term culture.

The cell morphology and expression of differentiated functions of primary rat hepatocytes on a titanium dioxide (TiO(2)) gel surface were investigated. Polystyrene culture dishes were coated with TiO(2) gel by spin-coating an ethanol solution of titanium n-butoxide, hydrolyzing in a humidity chamber and drying with nitrogen gas. The TiO(2) gel layer formed on the polystyrene dishes was transparent and robust, and its surface was quite flat. Rat hepatocytes inoculated on the TiO(2) gel-coated polystyrene dishes gradually accumulated with increasing culture time, and then spontaneously formed many hepatocyte spheroids at 90 +/- 21 microm diameter from about 3 days of culture. The diameter of the spheroids increased during the culture, and was 151 +/- 43 microm at 14 days of culture. Ammonia removal and albumin secretion by hepatocytes on the TiO(2) gel-coated polystyrene dishes were maintained at a high level for at least 14 days of culture compared with on a type I collagen-coated dish and a non-coated polystyrene dish. These results indicate that TiO(2) gel is an adequate material for hepatocyte spheroid formation and long-term culture of spheroids.

Animals↗
PubMed2006

Dynamic magnetic resonance sialography as a new diagnostic technique for patients with Sjögren's syndrome.

OBJECTIVE: To evaluate the clinical utility of dynamic magnetic resonance (MR) sialographic images as a diagnostic tool for patients with Sjögren's syndrome. METHODS: The morphological findings and various kinds of functional parameters in volunteers on dynamic MR sialographic images were compared with those in five patients with definite Sjögren's syndrome. RESULTS: On the MR sialographs of all five patients with Sjögren's syndrome, the so-called 'apple-tree appearance' was seen. The difference in two functional parameters using the dynamic MR sialographic data was elucidated between the two groups. The maximum area of the detectable ducts in the group of patients was significantly smaller (P < 0.001) than that in the group of volunteers. The ratio of change in the detectable ducts in the group of patients was significantly lower (P = 0.011) than that in the group of volunteers. CONCLUSIONS: Our study suggests that dynamic MR sialographic data in addition to MR sialographic images might be useful for the diagnosis of Sjögren's syndrome.

Adult↗
PubMed2005

Intratumoural expression of thymidylate synthase is an independent predictor of prognosis in patients with squamous cell carcinoma of the tongue: results from a retrospective study.

The aim of this study was to assess the importance of immunohistochemical thymidylate synthase (TS) expression level as a prognostic marker in tongue cancer patients. In 140 patients with primary squamous cell carcinoma (SCC) of the tongue, intratumoural TS expression was evaluated by immunohistochemistry. The level of TS expression was determined by a semiquantitative scoring system, ranging from 1+ to 3+ according to the ratio of TS-positive cells. Of 140 patients, 64 (45.7%), 49 (35.0%) and 27 (19.3%) were assessed as 1+, 2+ and 3+, respectively. Univariate analyses demonstrated that both disease-free survival (DFS) and overall survival (OS) were significantly lower in patients with a TS 3+ tumour than in those with a TS 1+/2+ tumour (DFS: P = 0.0082, OS: P = 0.0100). In a multivariate analysis using the Cox regression model, cervical lymph-node status and TS expression level were selected as independent factors for DFS and OS. Maintenance adjuvant chemotherapy by oral 5-fluorouracil (5-FU) significantly improved DFS and OS in patients with a TS 1+/2+ tumour (DFS: P = 0.0027, OS: P = 0.0398). These data suggest that the level of immunohistochemical TS expression is an independent prognosticator in patients with tongue SCC, and may be useful in the selection of patients who would benefit from oral 5-FU adjuvant chemotherapy.

Adult↗
PubMed2005

Velar ascent and morphological factors affecting velopharyngeal function in patients with cleft palate and noncleft controls: a cephalometric study.

This study compares velar ascent and morphological factors affecting velopharyngeal function between patients with repaired cleft palate and noncleft controls from early childhood to puberty. Lateral cephalograms obtained at rest and during blowing from 61 patients with repaired unilateral cleft lip and palate (cleft group) and 82 noncleft controls (control group) were divided into four developmental stages according to age and were studied cross-sectionally. Indices of nasopharyngeal area were derived from a coordinate system and landmarks on lateral cephalograms. The cleft group had lesser velar ascent, more posterosuperior position of the posterior maxilla, shorter velar length, and lesser pharyngeal depth than did the control group. There was a strong correlation between the vertical position of the posterior maxilla and the pharyngeal depth in the cleft group. Discriminant analysis revealed that the cleft group could be discriminated from the control group primarily on the basis of pharyngeal depth, velar length, and velar ascent. Our results suggest that the posterosuperior position of the posterior maxilla in patients with repaired cleft palate, resulting in reduced pharyngeal depth, represents an effort to facilitate velopharyngeal closure by means of shorter velar length and lesser velar ascent.

Adolescent↗
PubMed2005

Utility of three dimension fast asymmetric spin-echo (3D-FASE) sequences in MR sialographic sequences: model and volunteer studies.

OBJECTIVES: To evaluate the utility of 3D-FASE for the visualization of salivary gland ducts for use in MR sialographic sequences. METHODS: We compared MR sialographic images and virtual endoscopic views from 3D-FASE with those from three kinds of sequences described by previous reports in a 3D parotid gland duct model and volunteer. The four sequences were two-dimension fast spin-echo (2D-FSE), three-dimension fast spin-echo (3D-FSE), two-dimension fast asymmetric spin-echo (2D-FASE), and three-dimension fast asymmetric spin-echo (3D-FASE). RESULTS: In the 3D parotid gland duct model, image visibility on visual score was clearest with 3D-FSE, followed by 3D-FASE (P = 0.028). In the volunteers, the visualization of images improved in the following order: 3D-FASE > 3D-FSE > 2D-FSE > 2D-FASE. CONCLUSIONS: The technique of 3D-FASE sequencing is more suitable and useful for MR sialography with an appropriate acquisition time.

Adolescent↗
PubMed2005

Differentiation effects by the combination of spheroid formation and sodium butyrate treatment in human hepatoblastoma cell line (Hep G2): a possible cell source for hybrid artificial liver.

The aim of this study was to investigate the feasibility of human hepatoblastoma cell line (Hep G2), which differentiates by spheroid formation, and treatment with sodium butyrate (SB) as a cell source for hybrid artificial liver (HAL). Hep G2 spontaneously formed spheroids in polyurethane foam (PUF) within 3 days of culture and restored weak ammonia removal activity. Treatment with SB, which is a histone deacetylase inhibitor, further increased the ammonia removal activity of Hep G2 spheroids in a concentration-dependent manner. The activation of ornithine transcarbamylase--a urea cycle enzyme--was significantly related to the upregulation of ammonia removal by spheroid formation, but scarcely contributed to the further upregulation following SB treatment. In contrast with ammonia removal, treatment with SB reduced the albumin secretion of Hep G2 spheroids in a concentration-dependent manner. In the PUF-HAL module in a circulation culture, the ammonia removal rate and albumin secretion rate (per unit volume of the module) of Hep G2 spheroids treated with 5 mM SB were almost the same as those of primary porcine hepatocyte spheroids. These results suggest that simultaneous use of spheroid formation and SB treatment in Hep G2 is beneficial in enhancing the functions of human hepatocytes with potential applications in regenerative medicine and drug screening.

Albumins↗
PubMed2004

Okadaic acid stimulates expression of Fas receptor and Fas ligand by activation of nuclear factor kappa-B in human oral squamous carcinoma cells.

In the present study, we used western blot and RT-PCR analysis to examine the expression of proteins and mRNAs of Fas receptor and Fas ligand in human oral squamous carcinoma SCC-25 cells treated with okadaic acid. Treatment with okadaic acid enhanced the expression of proteins and mRNAs of both Fas receptor and Fas ligand in SCC-25 cells. The amount of IkappaB-alpha in whole cell lysates decreased, while the level of NF-kappaB in nucleus increased, in the okadaic acid-treated cells. Okadaic acid-treatment also alters the cellular localization of NF-kappaB, from cytoplasm to nuclei. To investigate the activation of NF-kappaB in okadaic acid-treated SCC-25 cells, we performed electrophoretic mobility gel shift assay using nuclear extracts and the consensus oligonucleotide for NF-kappaB DNA binding site. The binding of nuclear proteins to the oligonucleotide of NF-kappaB increased when the cells had been treated with 20 nM okadaic acid for 4 h. We transfected the cells with pFLF1, which has the promoter region of Fas receptor gene containing NF-kappaB binding site. A luciferase reporter gene assay demonstrated that the activity in the cells transfected with pFLF1 and treated with 20 nM okadaic acid increased in a time-dependent manner and that the activity was more than three-fold over that in the control cells. Our results suggest that NF-kappaB activated at early stages in the okadaic acid-treated SCC-25 cells stimulated the promoter activity of Fas receptor in the cells leading to the apoptotic death of these cells.

Carcinoma, Squamous Cell↗
PubMed2003

The role of leptin during the development of mouse preimplantation embryos.

Leptin is known to regulate diverse reproductive functions, and recent studies have implicated involvement of leptin in the early mouse embryo development. The aim of the present study was to investigate the expression of leptin and its functional receptor (OB-Rb) in mouse oocyte and preimplantation embryo, and to examine whether leptin influenced the early embryo development. Leptin mRNA was detected in blastocyst and hatched blastocyst, and OB-Rb mRNA was detected in oocytes, 1-cell, 2-cell, morula, blastocyst and hatched blastocyst. As for the origin of leptin, leptin mRNA was identified in both the oviduct and uterus of the pregnant mouse. Furthermore, in the pregnant mouse, the levels of leptin in uterine fluid were higher than those in the non-pregnant mouse. Supplementation of culture medium with leptin promotes the development of preimplantation embryos from 2-cell stage to the blastocysts, fully expanded blastocysts and hatched blastocysts. Leptin significantly increased the total cell number of blastocysts, and the effect was preferentially observed in the trophectoderm. These findings raise the possibility that leptin regulates the development of mouse preimplantation embryo through a paracrine pathway.

Animals↗
PubMed2003

Expression of LDL receptor and uptake of LDL in mouse preimplantation embryos.

OBJECTIVES: The aim of this study is to address the role of low-density lipoprotein (LDL) on mouse preimplantation embryos. METHODS: The temporal expression of low-density lipoprotein receptor (LDLR) and side-chain cleavage cytochrome P450 (P450scc) mRNAs in mouse oocytes and preimplantation embryos up to the hatched blastocyst stage were analyzed by RT-PCR and nested PCR techniques. Simultaneously, the expression of LDLR in the protein level was analyzed by fluorescent immunohistochemistory at oocyte, 4-cell embryo and blastocyst. Uptake of LDL was analyzed using the LDL labeled with the fluorescent probe DiO. RESULTS: LDLR mRNA was detected at oocyte, 8-cell, morula, blastocyst and hatched blastocyst stages. P450scc mRNA was detected at oocyte, 1-cell, 2-cell, 4-cell, blastocyst and hatched blastocyst stages. LDLR protein was detected in blastocyst. P450scc protein was detected in oocyte, 4-cell, and blastocyst. LDL-DiO was taken into embryo at blastocyst stage and this uptake was competitively suppressed by excess unlabeled LDL. CONCLUSIONS: It is suggested from the present study that LDLR may play an essential role in uptake of exogenous LDL into blastocyst stage and cholesterol derived from LDL may be the source of steroid hormone synthesis.

Animals↗
PubMed2003

Enhancement of mitochondrial oxidative stress and up-regulation of antioxidant protein peroxiredoxin III/SP-22 in the mitochondria of human pre-eclamptic placentae.

A growing body of evidence indicates that the pathogenesis of pre-eclampsia is closely associated with oxidative stress occurring in mitochondria. In the present study, we evaluated the degree of mitochondrial lipid peroxidation by assessing the accumulation of 4-hydroxy-2-nonenal (HNE)-modified proteins and examined the expression of mitochondrial antioxidant protein peroxiredoxin III/SP-22 in normal and pre-eclamptic human placentae. The accumulation of HNE-modified proteins increased to a greater extent in both the mitochondria and cytosol of pre-eclamptic placentae than in those of normal placentae. Moreover, the accumulation of HNE-modified proteins was much more evident in the mitochondria than in the cytosol, indicating that lipid peroxidation occurred mainly in the mitochondria of pre-eclamptic placentae. The mRNA expression of peroxiredoxin III/SP-22 was increased about 2-fold in pre-eclamptic placentae compared to normal placentae. The protein levels of peroxiredoxin III/SP-22 were approximately 4-fold higher in pre-eclamptic placentae than in normal placentae. Immunohistochemistry of placental tissues showed that the levels of peroxiredoxin III/SP-22 protein were increased in the trophoblasts of floating villi, stromal cells of stem villi, and decidual cells in pre-eclamptic placentae. These results indicate that peroxiredoxin III/SP-22 plays a crucial role in the protection of placental function from oxidative stress occurring in mitochondria of pre-eclamptic placentae.

Adult↗
PubMed2003

Transfusion transmitted virus (TTV) in dental patients.

Transfusion transmitted virus (TTV) is a new DNA virus found in patients with post-transfusion hepatitis. The prevalence of this virus among dental patients has not been reported, therefore, the prevalence of TTV infection in consecutive dental inpatients was evaluated. TTV DNA was assayed by the polymerase chain reaction (PCR) in 441 dental inpatients with oral cancer (n=192) or oral cysts (n=249). The serum HBs antigen and HCV antibody as well as aspartate transaminase (AST), alanine transaminase (ALT), and gamma glutamyl transpeptidase (gamma-GTP) concentrations were also measured. Of 441 subjects, 137 were infected with TTV (31.1%). This prevalence of TTV was much higher than that of HBV or HCV (HBV 1.2%; HCV 6.0%) in these dental patients. There was no gender or age difference in the prevalence of TTV infection. Of the 192 patients with oral cancer, 57 subjects had TTV in their sera, while 80 of 249 with oral cystic disease had TTV. The prevalence of TTV was similar between the two different disease groups. Neither the serum ALT nor serum AST concentrations were different between the subjects positive and negative for TTV DNA. In hospitalized dental patients, 31.1% were infected with TTV. The prevalence of TTV was much higher than that of HBV or HCV. There was no difference in the prevalence of TTV between subjects with cancer and cysts. Dentists should maintain high standards of infection control when treating any dental patient.

Adolescent↗
PubMed2003

Effects of latency period in a rabbit mandibular distraction osteogenesis.

Recently, distraction osteogenesis has been widely used in the craniomaxillofacial skeleton. There are varying views, however, about the need for a latency period for mandibular distraction, which has been reported from 0 to 14 days. We used a rabbit model to determine the ideal latency period for mandibular distraction osteogenesis. We performed a subperiosteal corticotomy of the bilateral mandible and then applied an external device. We used 0-, 2-, 5-, and 10-day latency periods. Distraction was done at a rate of 0.5 mm per day (0.25 mm every 12 h) to elongate by 5 mm after each latency period. Hematoxylin-eosin stain was used for histologic observation, and bone labelling was observed with a fluorescence microscope. In the 0-day latency, the lengthened region was filled with fibrous tissue. Cartilage formed like isles along the lengthened edge. In the 10-day latency, the lengthened region was almost completely filled with woven bone. In the 2- and 5-day latency, there were mineralization zones at the periphery of this fibrous interzone. The primary osteon remodelling zones were located at both ends of the zones of mineralization zones. In the 5-day latency, new bone formation was observed around the periosteum.

Animals↗
PubMed2003

Whole body muscle hypertrophy from resistance training: distribution and total mass.

OBJECTIVE: To examine the absolute and relative changes in skeletal muscle (SM) size using whole body magnetic resonance imaging (MRI) in response to heavy resistance training (RT). METHOD: Three young men trained three days a week for 16 weeks. RESULTS: MRI measured total SM mass and fat free mass (FFM) had increased by 4.2 kg and 2.6 kg respectively after resistance training. CONCLUSIONS: RT induces larger increases in SM mass than in FFM. RT induced muscle hypertrophy does not occur uniformly throughout each individual muscle or region of the body. Therefore the distribution of muscle hypertrophy and total SM mass are important for evaluating the effects of total body RT on muscle size.

Adult↗
PubMed2003

Efficacy of a polyurethane foam/spheroid artificial liver by using human hepatoblastoma cell line (Hep G2).

We invesigated the availability of human hepatoblastoma cell line (Hep G2), compared with human primary hepatocytes (HH) and porcine primary hepatocytes (PH), as a cell source for the hybrid artificial liver support system (HALSS) by using polyurethane foam (PUF). All three kinds of hepatocytes spontaneously formed spherical multicellular aggregates (spheroids) of 100-200 microm diameter in the pores of PUF within 3 days of culture. In a PUF stationary culture, Hep G2 spheroids recovered the ammonia removal activity that was lost in monolayer culture, although the removal for each unit cell number was about one tenth that of HH spheroids and about one eighth of PH spheroids. The synthesis activities of albumin and fibrinogen of each unit cell number of Hep G2 were also upregulated by PUF spheroid culture, and were about twice as high as in monolayer culture. The albumin secretion activity of Hep G2 spheroids was almost the same as that of PH spheroids. HH scarcely secreted these proteins in this experiment, probably because they were cultured in a serum-free medium. In the PUF module in a circulation culture, HH had high ammonia removal and low synthesis activities similar to stationary culture. Hep G2 proliferated to a high cell density, such as about 4.8 x 10(7) cells/cm3-module at 10 days of culture. Although Hep G2 spheroids had low ammonia removal activity in each cell, the removal rate in the PUF module was almost the same as for PH at 7 days of culture because of the high cell density culture by cell proliferation. The albumin secretion rate by Hep G2 in the PUF module also increased with cell proliferation and was about 10 times higher than the initial for the rate for PH at 7 days of culture. These results suggest that Hep G2 is a potential cell source PUF-HALSS.

Albumins↗
PubMed2002

Okadaic acid stimulates apoptosis through expression of Fas receptor and Fas ligand in human oral squamous carcinoma cells.

Fas receptor is a member of a superfamily of receptors characterized by cysteine-rich motifs in the extracellular domain of the molecule. Binding of Fas ligand to Fas receptor leads to activation of the latter and the induction of intracellular signals that result in apoptotic cell death. In the present study, we used reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis to examine the expression of mRNAs and proteins of Fas receptor and Fas ligand in human oral squamous carcinoma SCC-25 cells treated with okadaic acid. The PCR product of Fas receptor mRNA was detected in the cells and a protein with an estimated molecular weight of 35,000 was also expressed in them. Expression of Fas receptor mRNA stimulated by okadaic acid was elevated in dose- and time-dependent manners as judged by semiquantitative RT-PCR analysis, with the maximum expression level at 50 nM and 8 h treatment. Fas ligand mRNA expression was also stimulated by okadaic acid in SCC-25 cells in dose- and time-dependent manners. Okadaic acid also stimulated the expression of Fas ligand protein in the cells. Okadaic acid in serum-free medium induced apoptosis in SCC-25 cells in a time-dependent manner up to 24 h as determined by nuclear condensation and fragmentation of chromatin and DNA ladder formation. The present results indicate that the expression of Fas receptor and Fas ligand is negatively regulated by a protein phosphatase(s) sensitive to okadaic acid and is involved in okadaic acid-induced apoptosis in SCC-25 cells. Our results also suggest that Fas receptor and Fas ligand system might regulate apoptosis in SCC-25 cells in an autocrine fashion.

Apoptosis↗