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Biomedical subjects

K Fujisawa

Publications and source records attributed to K Fujisawa.

At least 145 records · Page 8Linked to original sources

Glial fibrillary acidic protein expression in the developing human retina.

We have studied the expression of glial fibrillary acidic protein(GFAP), an astrocyte specific protein in the normal developing human retina using anti-GFAP antibody. GFAP positive cells were first detected at 24 gestational weeks(GW) in the nerve fiber and ganglion cell layers in the vicinity of the optic disc. Over subsequent weeks, GFAP positive cells covered larger regions of the retina. Some of the processes of these cells terminated in sucker like end-feet upon blood vessels of the nerve fiber layer. A second population of GFAP positive cells existed as perivascular glia in the nerve fiber layer in the early stage of fetal development. In the adult retina perivascular glia were found on vessels throughout the nerve fiber and in the inner portion of the inner plexiform layers. Staining of Müller cells end-feet was obtained only in the adult retina. These results support the views that in the human retina, GFAP positive cells first appear at 24 GW in the region near the optic disc, covering the whole retina at subsequent ages.

Adolescent↗

Direct suppression of human synovial cell proliferation in vitro by salazosulfapyridine and bucillamine.

OBJECTIVE: The mechanism of disease modifying antirheumatic drugs (DMARD) is incompletely understood. We investigated in vitro the effect of DMARD such as bucillamine (Buc), salazosulfapyridine (SASP), and D-penicillamine (D-Pen) on the proliferation of human synovial cells in patients with rheumatoid arthritis (RA). METHODS: We evaluated the inhibitory effect of DMARD on [3H]-thymidine incorporation and cytokine production in synovial cells from patients with RA. Moreover, the expression of cytokine and protooncogene mRNA in synovial cells was determined by reverse transcription polymerase chain reaction methods. RESULTS: The proliferation of synovial cells and interleukin 1 beta (IL-1 beta) and interleukin 6 (IL-6) production of synovial cells were significantly inhibited by Buc and SASP in the concentration range of 1 to 100 microM in a dose dependent manner. In contrast D-Pen had no apparent effect at the same concentrations. Subsequently, the inhibitory effects of these compounds on transcriptional regulation of IL-1 beta, IL-6, and c-fos, which are well known to play an important role in synovial cell proliferation, were clarified. Overexpression of c-fos mRNA was inhibited by Buc and SASP. Moreover, the combination of low dose Buc and SASP inhibited synovial cell growth and transcriptional regulation of these mRNA. CONCLUSION: DMARD may have a direct inhibitory effect on rheumatoid synovial cell proliferation without the involvement of other cellular factors, which may be a mechanism of clinical remission induced by DMARD in patients with RA.

Anti-Inflammatory Agents, Non-Steroidal↗

[Hb, C, D and E hemoglobinopathies].

The four commonest beta chain variants of human hemoglobin (Hb), i.e. Hbs C, D, E, and S were absent or quite infrequent in Japanese. They are occasionally found in visitors and immigrants to Japan recently. Geographical distribution, clinical expression, pathophysiology and diagnosis of Hbs C, D and E are briefly reviewed.

Hemoglobin C Disease↗

Lysophosphatidic acid-induced activation of protein Ser/Thr kinases in cultured rat 3Y1 fibroblasts. Possible involvement in rho p21-mediated signalling.

Renaturation kinase assay was used to detect protein kinases activated by lysophosphatidic acid (LPA) in cultured rat 3Y1 fibroblasts. LPA activated several Ser/Thr protein kinases with apparent molecular weights of 145K, 85K, 64-65K (a doublet), and 60K (each named p145, p85, p64165 and p60, respectively) in addition to p43 mitogen activated protein (MAP)-kinase. Experiments using pertussis toxin and botulinum C3 exoenzyme showed that p145, p85, and p64165 kinases were activated by a pertussis toxin-insensitive rho p21-dependent pathway and that the activation of MAP-kinase was mediated by both the pertussis toxin-sensitive rho p21-independent and the pertussis toxin-insensitive rho p21-dependent pathways.

ADP Ribose Transferases↗

The effect of glucose and advanced glycosylation end products on IL-6 production by human monocytes.

To clarify the mechanism that causes elevation of plasma fibrinogen levels in diabetes, we examined the effect of high concentration of glucose and/or advanced glycosylation end products (AGEs) on the production of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) by human monocytes. Monocytes isolated from nine healthy volunteers were incubated with glucose, glucose with mannitol, or glucose with AGE-BSA for 24 or 48 h, respectively. IL-6 and TNF-alpha levels of culture supernatants were measured by ELISA methods. IL-6 and TNF-alpha levels of culture supernatants incubated with 22 mM or 33 mM glucose showed considerable increase over basal levels incubated with 11 mM glucose, whereas those levels incubated with high concentration of mannitol showed no increase. These two cytokine levels of culture supernatants, especially IL-6 level, showed synergistic elevation with AGE-BSA concentration. Our serial observation with treatment for lowering glucose levels showed that the diabetics with decreasing plasma fibrinogen levels also showed decrease in plasma IL-6 levels. In this study, we revealed the effect of glucose and AGEs on the production of IL-6 or TNF-alpha by human monocytes. These results suggest that hyperglycemia and AGEs will cause disregulated production of IL-6 and hyperfibrinogenemia in diabetics.

Diabetes Mellitus↗

Value of a dynamic MR scan in predicting vascular ingrowth from free vascularized scapular transplant used for treatment of avascular femoral head necrosis.

We have treated three patients with avascular osteonecrosis using vascularized scapular bone graft. To predict blood perfusion in both the diseased femoral head and the transferred bone, all the hips were followed up using dynamic magnetic resonance (MR) scans, performed 1 and 7 months after surgery. In the present cases, it was shown that conventional enhanced MR imaging sometimes depicts increased intensity in bone marrow without blood perfusion due to the leakage of gadolinium-DTPA (Gd-DTPA) from the capillaries surrounding the avascular tissue. It was found that Gd-DTPA remaining in the dead bone marrow resulted in a false-positive image. By contrast, the dynamic MR scan evaluated only those images taken before the leakage. This is one of the advantages of the dynamic study, which reflects actual blood flow in the bone. The fast rise in the time-intensity curve following bolus injection of Gd-DTPA indicates that there is fast blood perfusion in the bone. The dynamic MR scan has demonstrated that there is little blood perfusion in the diseased bone 1 month after the operation and that vascular ingrowth from the transferred bone flap proceeds gradually between 1 and 7 months after surgery. These findings indicate that the dynamic MR scan is very useful in demonstrating vascular ingrowth after surgery in avascular necrosis of the femoral head and can be a reliable monitoring technique for anastomotic patency of the vascularized bone flap.

Adolescent↗

Elongation of wallerian degenerating nerve with a tissue expander: a functional, morphometrical, and immunohistochemical study.

The purpose of this experimental study was to investigate the usefulness and mechanism of the expansion of wallerian degenerating nerve. The study consisted of two experiments: Experiment I, functional and morphometrical analysis, and Experiment II, immunohistochemical analysis. In Experiment I, the rat nerve crush model was used to assess the effects of mechanical expansion of wallerian degenerating nerves on axonal regeneration. In Experiment II, the rat sciatic nerve cut model was used to investigate the effects of nerve expansion on Schwann cell events in wallerian degenerating nerves. In both experiments, nerve expansion was carried out between days 5 and 9 after nerve injury, using a rubber tissue expander placed beneath the sciatic nerve. In Experiment I, rats were divided into the following three groups according to the volume of saline injected: control group (nerves were crushed, without saline injection); 8-ml injection group; and 11-ml injection group. Functional recovery was assessed using the sciatic functional index until 54 days after nerve injury. Rats in all three groups showed good functional recovery, and the morphometrical analysis revealed no significant differences among the three groups. In Experiment II, anti-S-100 protein polyclonal antibody and anti-proliferating cell nuclear antigen monoclonal antibody were used to identify proliferating Schwann cells. Rats were divided into two groups: control group (nerves were cut, without expansion) and nerve expansion group. In the control group, proliferating Schwann cells were observed only between days 3 and 7. By contrast, these cells continued to be seen in the expanded nerves until day 16. These results suggest that the expansion of wallerian degenerating nerve does not have a deleterious effect on the axon-promoting property of Schwann cell tubes and that the expansion is dependent not only on the viscoelasticity of the nerves but also on enhanced proliferation of Schwann cells.

Animals↗

Osteogenesis by human osteoblastic cells in diffusion chamber in vivo.

Osteogenic potential of osteoblastic cells isolated from human bone was evaluated by a diffusion chamber method. Cells placed in diffusion chambers were implanted intraperitoneally into the athymic mice. The diffusion chambers cultured in vivo were harvested and examined after implantation for 6-8 weeks. The content of the chamber was proved by a soft roentogenogram to contain the radioopaque area. Light microscopic study revealed that this area was made up of bone-like nodule. Within the diffusion chambers, the cell layers were observed alongside the interior surface of the membrane filters, and mineralized nodules were formed among the cell layers. The mineralized nodules were confirmed by staining with the von Kossa technique for calcium mineral deposits. In electron microscopic study, the osteoblastic cells had a relatively large nuclei, and an abundant rough endoplasmic reticulum produced numerous extracellular matrix. In the bone-like nodules, the osteoblastic cells were surrounded by a heavily mineralized matrix with nonmineralized matrix separating the osteoblastic cells from the mineralized matrix. The mineralized matrix contained well-banded collagen fibrils. Matrix vesicles and collagen fibrils which were closely associated with mineral deposition were observed at the mineralizing front. These results together with our previous report [13] indicate that isolated human osteoblastic cells possessed osteogenic potential in vivo as well as mineralization activity in vitro.

Animals↗

Reduction of hyperlipidemia and proteinuria without growth retardation in nephritic rats by a methionine-supplemented, low-soy-protein diet.

Effect of a low-soy-protein-isolate (SPI) diet supplemented with methionine on hyperlipidemia, proteinuria, and hypoalbuminemia was studied in rats with nephrotoxic serum nephritis (NSN). Rats were fed experimental diets for 14 d after an injection of nephrotoxic serum. An 8.5%-SPI diet (8.5S), as compared with a basal 20%-SPI diet (20S), improved the hyperlipidemia, proteinura, and hypoalbuminemia secondary to NSN but retarded the growth of rats. The addition of 0.3% methionine to 8.5S (8.5SM) alleviated the growth retardation without loss of the above-mentioned beneficial effects. 8.5SM was found to suppress hepatic cholesterol synthesis compared with 20S. These results suggest that the methionine-supplemented low-SPI diet has a beneficial effect on hyperlipidemia, proteinuria, and hypoalbuminemia without inducing either growth retardation or severe fatty liver in nephritis. They also suggest that the hypocholesterolemic effect of 8.5SM in nephritic rats may be partly attributable to reduced hepatic cholesterol synthesis.

Animals↗

Use of standardized protease enzymes for antibody screening of blood donor samples with the microplate system AutoAnalyzer.

Papain, bromelin and ficin can be standardized by the casein method for use in red blood cell antibody screening tests. The minimal and optimal enzyme activity for detecting blood group antibodies in donors, using the new Automated Pre-Transfusion Blood Testing System Olympus PK7200 by the two-stage method for all three enzymes, is one casein unit. One casein unit of proteinase activity changed the red blood cell surface charge to a low plateau value as measured by electrophoretic mobility and sialic acid content, and removed sterically inhibiting structures of surface protein as detected by SDS-PAGE.

Autoanalysis↗

Autoantibodies and CD5+ B cells in childhood onset immune thrombocytopenic purpura.

We evaluated platelet associated immunoglobulin (PIag) G, PaIgM, platelet associated autoantibodies to platelet glycoprotein IIb/IIIa (Pa-GPIIb/IIIa), the percentage of CD5+ B cells and the amount of platelet-bound anti-GPIIb/IIIa monoclonal antibody (mAb) in the peripheral blood of 29 patients with childhood onset chronic immune thrombocytopenic purpura (c-ITP). The percentage of CD5+ B cells ranged from 2 to 8% (4.7 +/- 2.0) in control patients and 1 to 18% (6.2 +/- 4.2) in the ITP patients. There was no overall significant difference between the two groups, but the percentage of CD5+B cells in six of the ITP patients was higher than the mean + 2 s.d. of the controls. There was a significant correlation between the percentage of CD5+ B cells and PaIgM (y = 1.73x + 13.4, r=0.40, P < 0.05). This finding is the basis for the speculation that CD5+ B cells may play an important role in the production of PaIgM in vivo. There was no correlation between the amounts of PaIgG and Pa-GPIIb/IIIa). This suggests that the amount of PaIgG does not accurately reflect of the amount of Pa-GPIIb/IIIa. Furthermore, we have demonstrated that autoantibodies to GPIIb/IIIa are directed to more that one epitope.

Adolescent↗

Hurler syndrome with severe complication in post-bone marrow transplantation course: life threatening interstitial pneumonitis and hypertension.

Bone marrow transplantation (BMT) was performed in a 3 year old patient with Hurler syndrome. The post-BMT course was complicated by interstitial pneumonitis and severe hypertension, which were life threatening. The patient responded well to therapy and recovered. BMT in this patient resulted in significant clinical improvement in the signs and symptoms of Hurler syndrome. Biochemical improvement, including elevated alpha-L-iduronidase activity in white blood cells and decreased urinary glycosaminoglycan excretion was significant. However, skeletal and neurological impairment were not improved. We conclude that BMT for Hurler syndrome should be performed at an earlier stage, before severe neuronal damage has occurred. Moreover, BMT is a high risk procedure and there will always be a possibility that life threatening complications will occur, as in our case.

Bone Marrow Transplantation↗

Immunohistochemical and biochemical detection of low density lipoprotein receptors in cultured rat mesangial cells.

The expression of low density lipoprotein (LDL) receptors by cultured rat mesangial cells was demonstrated using immunohistochemical and biochemical methods. Using a mouse monoclonal anti-human LDL receptor antibody, the immunofluorescence technique was applied to cultured mesangial cells and showed granular staining. Immunoblotting analysis of the membrane fraction of cultured mesangial cells showed a single band with a protein of approximately 130,000 molecular weight. In addition, [125I]LDL binding and the uptake of [125I]LDL by cultured mesangial cells were studied. Binding and uptake both reached an equilibrium after about 30 min of incubation. A 50% reduction in [125I]LDL (20 micrograms protein/ml) binding and uptake occurred when unlabelled LDL was added to cultures at 20-40 micrograms protein/ml. Addition of high density lipoprotein without apoE to the culture medium did not induce competitive inhibition of [125I]LDL binding and uptake by mesangial cells. These findings suggest that cultured mesangial cells have the capacity to express an LDL receptor that regulates the cellular uptake of LDL.

Animals↗

Evaluation of lens transparency changes through photographed images during a 13-month observation period.

Since the development of the anterior eye segment analysis system, several new types of anterior eye segment biometry have been performed. The main aim of this study was to evaluate whether changes in cataractous progression or an increase in lens transparency loss are detectable during a relatively short period of 13 months by measuring the intrapupillary opaque shadow area through retroillumination images or by calculating the light scattering intensity at the deepest cortical layer of the lens through Scheimpflug slit images. Secondly, the relationship between maximally dilated pupil sizes and patients' ages and that between cases with and without diabetes were studied. Thirty-one eyes (49.2%) of sixty-three cataractous lenses showed more than 5% increase in the opaque shadow area. Forty-five eyes (60.0%) showed more than a 5% increase in light scattering intensity. 92.5% of diabetic eyes and 92.3% of nondiabetic eyes showed pupil sizes over 6.5 mm after an instillation of mydriatica. In our study the applied method guaranteed a high reproducibility; thus is might be possible to detect an increase in cataractous changes and lens transparancy in around 50% of examined subjects in a period as short a 1 year. For the evaluation of cataract progression through a retroillumination image, the recommendable pupil size is > or = 6.5 mm.

Aged↗

Infant with thanatophoric dwarfism in triplet pregnancy.

The case of a Japanese female infant with thanatophoric dwarfism, a triplet, is reported. The diagnosis was made at 18 weeks' gestation. Triplets were delivered at 30 weeks' gestation by cesarean section. Two infants, both males, were normal; the female with dwarfism died of respiratory distress 34 min after delivery. This is the first known case of one fraternal triplet being affected by thanatophoric dwarfism.

Fatal Outcome↗