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Biomedical subjects

K Fujimoto

Publications and source records attributed to K Fujimoto.

At least 325 records · Page 18Linked to original sources

Generalizability of the limits of stability test in the evaluation of dynamic balance among older adults.

OBJECTIVE: Reliability of platform posturography tests is essential for the identification and treatment of balance-related disorders. The purposes of this study were to establish the reliability of the limits of stability (LOS) test and to determine the relative variance contributions from identified sources of measurement error. DESIGN: Generalizability theory was used to calculate (1) variance estimates and percentage of variation for the sources of measurement error, and (2) generalizability coefficients. Random effects repeated measures analysis of variance (RM ANOVA) was used to assess consistency of measurements across both days and targets. PARTICIPANTS: Thirty-eight community-dwelling older adults with no recent history of falls. MAIN OUTCOME MEASURES: Outcome measures derived from the LOS tests included movement velocity (MV), maximum center of gravity (COG) excursion (ME), end point COG excursion (EE), and directional control (DC). RESULTS: Estimated generalizability coefficients for 2 and 3 days of testing ranged from .69 to .91. Relative contributions of the day facet were minimal. The RM ANOVA results indicated that for three of the movement variables, no significant differences in scores were observed across days. CONCLUSIONS: The 75% and 100% LOS tests are reliable tests of dynamic balance when administered to healthy older adults with no recent history of falls. Dynamic balance measures were generally consistent across multiple evaluations.

Aged↗

Effects of structural modulation on biological activity of bombesin analogues with (E)-alkene bond.

The specific bombesin receptor antagonist, (E)-alkene bombesin isostere (EABI-1), [D-Phe6,Leu13psi[(E)CH=CH]Leu14]bombesin(6-14) is a potent antagonist in terms of inhibition of bombesin-stimulated amylase release from rat pancreatic acini. This study examined the effects of EABI-1 (L-L diastereomer) and three novel bombesin analogues on amylase release in rat pancreatic acini. EABI-2 is a L-D diastereomer of EABI-1. EABI-3 is an analogue, of which leucine at position 13 of EABI-1 was replaced with valine. EABI-4 is a L-D diastereomer of EABI-3 (L-L). The order of agonist potency was EABI-2>EABI-3>EABI-4. EABI-1 showed no agonist activity at concentrations up to 100nM. On the other hand, all of four analogues had antagonist activity. The order of antagonist potency was EABI-1>EABI-3>EABI-4>EABI-2. EABI-1 was a complete antagonist, EABI-2 and EABI-3 were partial agonists, and EABI-4 had a weak agonist effect. The present study provides a useful information on the future development of peptide analogues for anticancer agents and biological tools for investigating actions of bombesin family peptides.

Amylases↗

Multiple intramedullary spinal sarcoidosis: case report.

BACKGROUND: According to past reported cases, spinal intramedullary sarcoidosis has the radiologic characteristics of a single enhanced lesion with cord swelling. However, it is difficult to make a diagnosis using only radiologic examinations. Including our case, 20 cases have been reported of intramedullary spinal sarcoidosis. Only six cases were diagnosed as primary spinal sarcoidosis. We present a rare case of multiple spinal intramedullary sarcoidosis without cord swelling. CASE DESCRIPTION: This 63 year-old man was afflicted with progressive paraparesis and numbness of the lower extremities. Magnetic resonance imaging showed intramedullary lesions without cord swelling. The patient underwent biopsy for diagnosis and the specimen showed a noncaseating granuloma mainly composed of epitheloid cells. Postoperative corticosteroid therapy was effective and the lesion disappeared 1 month after the operation. CONCLUSIONS: Biopsy is a less invasive method and is useful for early diagnosis. Early diagnosis is important for spinal sarcoidosis so that high-dose corticosteroid therapy can be commenced while the lesion still has a good chance of being successfully treated.

Humans↗

Effects of interleukin-11 on carboplatin-induced thrombocytopenia in rats and in combination with stem cell factor.

The effects of interleukin-11 (IL-11) which stimulates megakaryopoiesis and thrombopoiesis and/or stem cell factor (SCF) which stimulates multiple lineage cells in the peripheral blood by an increase in marrow cellularity on hematopoietic suppression in carboplatin (CBDCA)-treated rats were determined. CBDCA was administered to rats at a dose of 35 mg/kg as a single intraperitoneal bolus on day 0. IL-11 (20 micrograms/day) was given subcutaneously for 10 days from day 5 after CBDCA treatment. IL-11 ameliorated the suppression of hematopoiesis in rats treated with CBDCA. Especially, the production of the platelets was stimulated by IL-11 more markedly than that of cells of other lineages. However, the combination of SCF and IL-11 intensified the CBDCA-induced suppression of hematopoiesis. These findings may be helpful in the design of future therapies to prevent or treat thrombocytopenia induced by chemotherapy.

Animals↗

Activation of prophenoloxidase A1 by an activating enzyme in Drosophila melanogaster.

An activating enzyme for prophenoloxidase A1 was isolated from pupae of Drosophila melanogaster, and the activation of purified prophenoloxidase A1 with this enzyme was analyzed. The purification included ammonium sulfate fractionation, DEAE-cellulose, Superdex 75, arginine-Sepharose and hydroxyapatite column chromatography. The prophenoloxidase activating enzyme was determined to be a 28.5-kDa protein consisting of a single polypeptide. The kinetics of the activation reactions was unusual in that the final levels of phenoloxidase activity varied depending on the initial concentrations of the activating enzyme, not those of the prophenoloxidase. The activation was effectively suppressed by the inhibitors of trypsin-type serine protease. The protein has amidolytic activity, and Boc-Val-Pro-Arg-MCA was the best substrate among the synthetic substrates examined. The molecular mass of the activated phenoloxidase was smaller than that of the prophenoloxidase, indicating that a 5-kDa peptide was released from the prophenoloxidase by limited proteolysis with the activating enzyme. The cleavage site of prophenoloxidase A1 was shown to be between Arg and Phe at positions 52 and 53.

Amidohydrolases↗

A new prognostic strategy for gastric carcinoma: mRNA expression of tumor growth-related factors in endoscopic biopsy specimens.

OBJECTIVE: The study analyzed the prognostic value of the transcription of several tumor growth-related genes in gastric carcinoma biopsy specimens. SUMMARY BACKGROUND DATA: The nodal status is one of the most significant prognostic factors in gastric carcinoma. There are, however, no satisfactory parameters for the preoperative assessment of nodal status. METHODS: A reverse transcriptase-polymerase chain reaction analysis was used to analyze the transcription of several tumor growth-related genes in endoscopic biopsy specimens from 78 gastric carcinomas. The factors examined were cyclin D1, cyclin E, urokinase-type plasminogen activator, 72-kd type IV collagenase, vascular endothelial growth factor, platelet-derived growth factor-A (PDGF-A), transforming growth factor-beta, and interleukin-10. The relation between the mRNA expression and the clinical pathologic parameters was analyzed statistically. RESULTS: The incidence of PDGF-A (p = 0.010) and transforming growth factor-beta (p = 0.009) mRNA expression increased as the pathologic stage advanced. Nodal metastasis correlated with cyclin D1 (p = 0.045), cyclin E (p = 0.037), urokinase-type plasminogen activator (p = 0.047), and PDGF-A (p = 0.003) mRNA. Interestingly, the expression of PDGF-A mRNA showed a positive correlation (p = 0.004) with the early presence of lymph node metastases. CONCLUSIONS: Tumor growth-related factor mRNA in biopsy specimens may be a new prognostic tool.

Biopsy↗

Role of apoptosis in duct obstruction-induced pancreatic involution in rats.

It has been recognized in mammals that after pancreatic duct obstruction, acinar cells progressively disappear and pancreatic islets are preserved. Previous studies by electron microscopy have suggested the involvement of apoptosis in acinar cell deletion. In the present study, we employed molecular biological methods and investigated whether acinar cell deletion is due to apoptosis. In male Sprague-Dawley rats, pancreatic duct ligation was performed through a left paramedian incision. Pancreatic tissue was studied at each of the following intervals after ligation: 3, 6, 12, 18, and 24 h and 2, 3, 5, and 7 days. DNA fragmentation was determined by in situ labeling of DNA strand breaks on tissue sections [fluorescein-labeled terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling method (TUNEL)] and by electrophoretic detection of the fragments of extracted DNA. Tissue sections were also examined by hematoxylin/eosin staining and immunohistochemical staining of insulin. Pancreatic duct ligation induced acinar cell deletion by day 5. Pancreatic tissue from control rats demonstrated no TUNEL-positive nuclei. In contrast, acinar cells from rats 12 h to 5 days after duct ligation showed TUNEL-positive nuclei. The number of TUNEL-positive nuclei was maximum 2 days after duct ligation. Electrophoresis showed DNA fragmentation after duct ligation. Control rats showed a genomic DNA pattern. Islets were preserved throughout the experimental period in duct-ligated rats and control rats. The results suggest that apoptosis may be the dominant form of acinar cell death in the rat pancreatic duct ligation model.

Amylases↗

Expression of Bcl-2 and PCNA in duct cells after pancreatic duct ligation in rats.

Obstruction of the pancreatic duct induces acinar cell deletion followed by duct proliferation and interstitial fibrosis. Apoptosis has been reported to be involved in the induction of acinar cell deletion after pancreatic duct ligation (PDL) in rats, however, the mechanism of pancreatic duct cell proliferation is still unknown. We hypothesized that Bcl-2 (antiapoptosis protein) and PCNA (cell cycle-related protein) could be involved in the mechanism of pancreatic duct cell proliferation after PDL. In PDL, rats, acinar cells decreased in number and disappeared completely after duct ligation and duct-lining cells increased in number and formed duct-tubular complexes. Immunohistochemical study showed that PCNA expression appeared in the ductules and centroacinar cells from early stages after duct ligation and that Bcl-2 expression in duct cells, which was faint in normal pancreas, increased significantly when acinar cells were diminishing. Western blotting demonstrated that Bcl-2 was detected as a single band at 26 kDa, and the intensity of Bcl-2 in PDL rats was approximately ninefold stronger than in normal pancreas. Expression of Bcl-2 and PCNA after pancreatic duct ligation may be related to the prevention of apoptosis and cell proliferation of pancreatic duct cells in rats.

Animals↗

Studies of bronchial asthma induced by chironomid midges (Diptera) around a hypereutrophic lake in Japan.

There have been few reports on hypersensitivity to chironomid midges in bronchial asthmatic patients around the area of hypereutrophic natural lakes, which have been notorious as an environmental hazard due to the massive occurrence of adult chironomids during several periods of the year. Our study investigated IgE antibodies to chironomid midges in bronchial asthmatic patients around the Lake Suwa area in comparison with those of the Matsumoto area (control area). A total of 123 adult patients with bronchial asthma were investigated by measurement of IgE antibodies with extracts of three chironomid midges (Chironomus yoshimatsui, C. plumosus, and Tokunagayusurika akamusi), mite, and silkworm. In addition, in the allergy testing, 12 common inhalant antigens were used. Of 123 adult patients with bronchial asthma, 65 (52.8%) produced positive allergy tests. Thirty-three (50.8%) were positive to mite, 28 (43.1%) to silkworm, 11 (16.9%) to C. yoshimatsui, eight (12.3%) to C. plumosus, and three (4.6%) to T. akamusi. We compared our results with the previous reports. The number of positive tests to silkworm in the Lake Suwa area was higher than in other areas. However, C. plumosus and T. akamusi showed a lower number of positive reactions. We considered the lower positive number of C. plumosus and T. akamusi tests in the Lake Suwa area to be related to the advanced age of patients in this area. The chironomids are an important cause of asthma, together with mite and silkworm, in the Lake Suwa area, but affect old asthmatic patients less than asthmatic children.

Administration, Inhalation↗

Analysis of bronchoalveolar lavage fluid in patients with chronic hepatitis C before and after treatment with interferon alpha.

BACKGROUND: Previous studies have shown that patients with idiopathic pulmonary fibrosis (IPF) were more likely to be seropositive for hepatitis C virus (HCV) than normal controls, and that patients with chronic hepatitis C treated with interferon alpha (IFN-alpha) sometimes developed pulmonary fibrosis. The possibility that HCV infection and/or treatment with IFN-alpha are involved in the pathogenesis of pulmonary fibrosis or alveolitis was investigated. METHODS: A prospective non-randomised study was performed in 13 healthy controls and in patients with chronic hepatitis C before (n = 13) and after (n = 10) treatment with IFN-alpha. Bronchoalveolar lavage (BAL) fluid cell counts, ratios and T cell subsets, and the concentrations of interleukin (IL)-1 beta, tumour necrosis factor(TNF)-alpha, and hepatocyte growth factor (HGF) were measured. RESULTS: Lymphocyte counts in the BAL fluid were significantly increased in both groups of patients (median (range) values: before treatment, 36.8 (1.5-226.0); after treatment, 16.2 (4.5-97.6)) compared with the normal controls (3.3 (0.5-32.3)). In the pretreatment group the activated T cell (HLA-Dr positive) count was also increased (51 (40-74)) compared with that in the normal controls (27 (4-52)), but after treatment it was decreased (40 (0-76)) compared with the pretreatment count. Administration of IFN-alpha did not affect these parameters. IL-1 beta, TNF-alpha, and HGF were not detected. CONCLUSIONS: These findings suggest that HCV infection is associated with increased counts of lymphocytes and neutrophils in BAL fluid and that treatment with IFN-alpha appears to alter lymphocyte surface markers.

Adult↗

Role of neutrophils in cerulein-induced pancreatitis in rats: possible involvement of apoptosis.

We investigated the role of neutrophils and the involvement of apoptosis in cerulein-induced acute pancreatitis. Male Sprague-Dawley rats were divided into 2 groups. In the control group, acute pancreatitis was induced by subcutaneous injections of cerulein. In methotrexate-treated group, the rats received intraperitoneal injections of methotrexate to produce neutrophil depletion before the injections of cerulein. The rats were sacrificed at the indicated time points until 72 h after the first injection of cerulein. Neutrophil depletion ameliorated pancreatic edema and vacuole formation in acinar cells during the early stages of cerulein-induced acute pancreatitis. Electron microscopy, DNA gel electrophoresis and in situ nick end-labeling revealed the involvement of apoptosis in acinar cells in cerulein-induced acute pancreatitis. Furthermore, the number of apoptotic acinar cells in neutrophil-depleted rats showed an about 2-fold increase during the late stages when compared with those in the control rats. Our results suggest that neutrophil depletion in cerulein-induced pancreatitis leads to amelioration of pancreatic injury during the early stage, and enhancement of apoptosis by neutrophil depletion occurs during the late stage.

Acute Disease↗

Cell activation by the micropatterned surface with settling particles.

Surface topography plays an important role in cell orientation and morphogenesis. In this study, we prepared a micropatterned surface with settling particles to obtain more detailed information about the cell recognition against the microstructured surface. Core-shell type particles having a poly-(N-isopropylacrylamide) (polyNIPAM) shell were prepared by seeded polymerization. Particles were settled on a polystyrene (PSt) flat dish by the spinner to prepare a micropatterned surface with settling particles. It could be seen that the polyNIPAM shell shrunk above and swelled below the LCST. For comparison, a thermosensitive flat surface was prepared by the graft polymerization of NIPAM. No morphologic change of cells contacting the both surfaces was observed with either an optical or a scanning electron microscope. Moreover, particles could move or roll on these surfaces when shaking the dishes. The weak interaction between neutrophil-like cells and the micropatterned surface with settling particles or the polyNIPAM-grafted surface was estimated by measurement of active oxygen released by cells. A little release could be observed at both 25 and 35 degrees C. The amount of released active oxygen at 35 degrees C was slightly larger than at 25 degrees C. When the temperature was suddenly changed, the dynamic changes of particle shape and size resulted in the excess release of active oxygen from cells contacting the micropatterned surface with settling particles. Meanwhile no stimulation could be observed in the polyNIPAM-grafted surface even if the temperature is suddenly changed. These results indicate that the micropatterned surface with settling particles can induce the dynamic stimulus at a patterned input mode.

Acrylic Resins↗

The relations between expiratory chest CT using helical CT and pulmonary function tests in emphysema.

Chest computed tomography (CT) and pulmonary function tests are usually used for the evaluation of emphysema. We performed the present study to evaluate more accurately the relationship between the degree of morphological change and the functional abnormality in emphysema. We used a helical CT apparatus to obtain the CT images both at full inspiration and full expiration. We classed the degree of emphysema into 5 grades (0-4) by visual observation on CT image obtained at the two levels, upper and lower fields, on each side. We assigned each of these grades a visual score. We also calculated the average ratio of CT numbers of each of the lung fields at full expiration to that at full inspiration for each level. We designated this the E/I ratio. We then examined the relationship between the findings acquired by each of these two methods and pulmonary function test results. The visual score showed correlations with FEV1(% predicted) (-0.592, p < 0.0001), RV/TLC(%)(0.425, p < 0.025), and DL(CO)/VA(% predicted)(-0.538, p < 0.0001). The E/I ratio showed correlations with FEV1(% predicted) (-0.620, p < 0.0001), RV/TLC(%)(0.661, p < 0.0001), and DL(CO)/VA(% predicted) (-0.299, p < 0.05). Compared with the E/I ratio, the visual score showed much higher correlation with DL(CO)/VA(% predicted), but the E/I ratio showed stronger correlation with RV/TLC(%) than did the visual score. The visual score may reflect the degree of emphysema, whereas the E/I ratio reflects the air trapping. These findings suggest that the helical CT is useful in the evaluation of emphysematous changes and that the E/I ratio reflects the air trapping.

Aged↗

Metal sandwich method to quick-freeze monolayer cultured cells for freeze-fracture.

We describe a simple quick-freezing method to obtain a large fractured plane of the plasma membrane from monolayer cultured cells. Cells were grown on thin gold foil, inverted on a thin layer of gelatin on thin copper foil, and frozen by a quick press between two gold-plated copper blocks precooled in liquid nitrogen. The frozen cell sandwich was mounted on the cold stage of a freeze-fracture device with the gold side up and was fractured by separating the sandwich with a cold fracture knife. When this technique was applied to confluent monolayer cells, large replicas of the E-face of the upper plasma membrane and the P-face of the lower plasma membrane were obtained. The present metal sandwich method is simple, does not require any expensive equipment, and provides a large fracture plane of the plasma membrane for subsequent histochemical manipulation.

Cells, Cultured↗

Occludin as a possible determinant of tight junction permeability in endothelial cells.

Endothelial cells provide a crucial interface between blood and tissue environments. Free diffusion of substances across endothelia is prevented by the endothelial tight junction, the permeability of which varies enormously depending on tissue. Endothelial cells of the blood-brain barrier possess tight junctions of severely limited permeability, whereas those of non-neural tissue are considerably leakier, but the molecular basis for this difference is not clear. Occludin is a major transmembrane protein localizing at the tight junction. In this study, we show, by immunocytochemistry, that occludin is present at high levels and is distributed continuously at cell-cell contacts in brain endothelial cells. In contrast, endothelial cells of non-neural tissue have a much lower expression of occludin, which is distributed in a discontinuous fashion at cell-cell contacts. The apparent differences in occludin expression levels were directly confirmed by immunoblotting. The differences in occludin protein were reflected at the message level, suggesting transcriptional regulation of expression. We also show that occludin expression is developmentally regulated, being low in rat brain endothelial cells at postnatal day 8 but clearly detectable at post-natal day 70. Our data indicate that regulation of occludin expression may be a crucial determinant of the tight junction permeability properties of endothelial cells in different tissues.

Amino Acid Sequence↗

Dynamics of connexins, E-cadherin and alpha-catenin on cell membranes during gap junction formation.

We examined the dynamics of connexins, E-cadherin and alpha-catenin during gap-junction disassembly and assembly in regeneration hepatocytes by immunofluorescence microscopy, and immunogold-electron microscopy using SDS-digested freeze-replicas. The present findings suggest that during the disappearance of gap junctions most of the gap junction plaques are broken up into smaller aggregates, and then the gap junction proteins may be removed from the cell membrane, but some of the connexons or connexins remain dispersed in the plane of membrane as pure morphologically indistinguishable intramembrane proteins. Double-immunogold electron microscopy using a polyclonal antibody for connexins and a monoclonal antibody for E-cadherin or alpha-catenin revealed co-localization of these molecules at cell-to-cell contact sites during the reappearance of gap junction plaques. This implies that, at least in regenerating hepatocytes, the cadherin-catenin complex-mediated cell-to-cell contact sites act as foci for gap junction formation. In addition, connexin-immunoreactivity was also observed along tight junctional strands, suggesting that the gap junction may also form along the tight junctions.

Animals↗