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Biomedical subjects

H Fujii

Publications and source records attributed to H Fujii.

At least 559 records · Page 31Linked to original sources

Molecular abnormality of a unique Japanese glucose-6-phosphate dehydrogenase variant (G6PD Kobe) with a greatly increased affinity for galactose-6-phosphate.

Systematic molecular analysis of a Japanese class 1 glucose-6-phosphate dehydrogenase (G6PD) variant (G6PD Kobe) cDNA revealed a unique nucleotide substitution (1318 C to T) in exon 11, which predicts a substitution of leucine for phenylalanine at residue 440. This substitution is located in a region surrounding the putative structural NADP-binding domain. The markedly abnormal kinetics of glucose-6-phosphate (G6P) of G6PD Kobe suggest the interaction between both NADP and G6P binding sites.

Base Sequence↗

Myelomonocytic crisis with t(5;17) and a p53 mutation in a patient with chronic myelogenous leukemia.

We report a 64-year-old Japanese man with chronic myelogenous leukemia (CML) who expired with myelomonocytic crisis. Cytogenetic analyses of chronic phase (CP) and accelerated phase (AP) cells revealed a Philadelphia chromosome and an isochromosome for the long arm of chromosome 17, i(17q). This karyotype was replaced by another karyotype in blast crisis (BC), resulting in near triploidy with t(5;17) (p15;p11) and loss of chromosome 17 pter-->p11. Interphase fluorescent in situ hybridization studies with a chromosome 17 specific alpha satellite DNA probe confirmed the presence of a clonal change in BC. In addition, single-strand conformation polymorphism analysis and PCR-direct sequencing of BC cells revealed a point mutation at codon 203 of the p53 gene, GTG to GAG (Val to Glu), and loss of the normal allele. In contrast, no alterations of the p53 gene were found in CP and AP cells. Therefore, progression of CML in this patient appeared to be related to loss of 17p, as well as a mutation in the p53 gene.

Alleles↗

Clinical significance of antibodies to native or denatured 60-kd or 52-kd Ro/SS-A proteins in Sjögren's syndrome.

OBJECTIVE: To evaluate the clinical significance of antibodies to native or denatured (anti-n or anti-d) 60- or 52-kd Ro/SS-A proteins (60K or 52K) in Sjögren's syndrome (SS). METHODS: The presence of antibodies to denatured and native Ro/SS-A proteins was determined by immunoblotting and immunoprecipitation, respectively. Salivary gland dysfunction was evaluated by salivary function scintigraphy. RESULTS: The incidence of anti-d-60K without anti-d-52K was lower among patients with systemic lupus erythematosus with SS (SLE/SS) and among those with primary SS, compared with patients who had SLE without SS, whereas anti-d-52K without anti-d-60K was more common in SLE/SS patients and primary SS patients than in SLE patients without SS. All of the patients with anti-Ro/SS-A had anti-n-60K. Serologic abnormalities and salivary gland dysfunction were associated with anti-n-60K in SS, whereas Hashimoto's thyroiditis in SS was related to anti-d-60K. Anti-d-52K was not associated with any extraglandular or glandular symptoms in SS. CONCLUSION: The data indicate that anti-n-60K, which appears to recognize conformational epitopes, is associated with clinical features of SS characterized by glandular dysfunction.

Autoantibodies↗

Blockade of liver macrophages by gadolinium chloride reduces lethality in endotoxemic rats--analysis of mechanisms of lethality in endotoxemia.

We investigated the effects of gadolinium chloride (GdCl3.6H2O), which blocks phagocytosis by liver macrophages, on the mortality, blood tumor necrosis factor (TNF) levels, and hepatotoxicity in a lethal endotoxic shock rat model system [10 mg/kg body weight lipopolysaccharide (LPS) intravenously]. With administration of GdCl3, twice at 0.5 or 5 mg/kg, the survival rate 24 h after LPS injection was 56% and 100%, respectively, whereas the level of TNF in blood was not affected. Microscopic investigation of the liver revealed that the focal necrosis of hepatocytes under endotoxemia was completely protected by the administration of GdCl3 at 5 mg/kg. We then investigated the effects of GdCl3 on superoxide (O2-) production by isolated liver macrophages in vitro. The O2- production by liver macrophages isolated from control rats was suppressed by GdCl3 in a dose-dependent manner. GdCl3 also had a cytotoxic effect on these macrophages. The enhanced O2- production by liver macrophages isolated from sublethal endotoxemic (1 mg/kg) rats was suppressed by pretreatment with GdCl3 (5 mg/kg). It was suggested that lethality in endotoxemia cannot be explained only by the degree of increase in blood TNF levels and that the mechanism by which GdCl3 reduces mortality and hepatotoxicity in endotoxemia possibly includes suppression of superoxide production by liver macrophages.

Animals↗

In vivo EPR studies of the metabolic fate of nitrosobenzene in the mouse.

We report the first demonstration of EPR spectroscopy to study free radical reactions in live mice and excised muscle tissue resulting from the metabolism of nitrosobenzene. A broad three-line EPR spectrum (aN = 11.6 G) appeared in the buttocks region of a mouse place in an L-band loop gap resonator after intramuscular or intraperitoneal injection of 0.2 mmol/kg nitrosobenzene. The signal intensity reached a maximum at 20 to 30 min and remained constant well beyond 2 h. If muscle tissue was dosed with nitrosobenzene and excised within 5 min, a similar three-line X-band EPR spectrum was obtained which was preceded by the rapid growth and subsequent decay of an EPR spectrum identical with that of the phenylhydronitroxide radical, which was presumably generated from reactions between nitrosobenzene and reducing agents in the blood or tissue such as NADH or ascorbic acid. A model system containing nitrosobenzene and unsaturated fatty acids (olive oil or animal fat) yielded an identical three-line spectrum resulting from radical adducts of nitrosobenzene across the double bond. Overall, these results suggest that the most probable mechanism in vivo was nitrosobenzene covalently adding ("binding") to polyunsaturated fatty acid clusters in fat or membranes.

Animals↗

Therapeutic response and potential pitfalls in phase I clinical trials of anticancer agents conducted in Japan.

The published reports of phase I clinical trials of anticancer agents conducted in Japan from 1981 to 1991 were reviewed. A total of 56 clinical studies that evaluated 38 different agents were reviewed. An average of five agents were studied each year. A total of 2200 patients had been recruited into the 56 clinical trials conducted during this period. A total of 91 patients (4.1%) responded to the treatment, with 23 showing a complete response (1.1%) and 48, a partial response (2.2%). In all, 62% of the responses were observed when patients were treated with doses ranging from 76% to 125% of the recommended doses for phase II studies. The response rates obtained for hematological malignancies were higher than those reported for other malignancies. The past status of phase I clinical trials in Japan can be summarized as follows. (1) A median of seven institutes participated in a single trial. The number of institutes participating correlated with the number of patients enrolled. However, too many institutes participated in a single phase I clinical trial in some studies. (2) The median duration of study for the clinical trials was 14 months. The duration of study was too long in some studies, considering the small number of patients enrolled. In conclusion, the methodology of phase I clinical trials of anticancer agents conducted in Japan should be improved in an efficient and scientific manner, especially for the testing of imported agents.

Antineoplastic Agents↗

Glucagon responses in rabbits with obstructive jaundice and a low energy status in the liver.

Glucagon has a choleretic effect and also stimulates energy-consuming reactions, such as gluconeogenesis and ureogenesis in the liver. The effect of glucagon on energy metabolism in the liver was analyzed in rabbits with obstructive jaundice that had severe liver damage, indicated by significantly lower hepatic energy charge levels. The gluconeogenetic responses to glucagon administration, as shown by increases in the plasma glucose levels, were usually observed in normal rabbits, but these responses were completely depressed after glucagon administration in rabbits with obstructive jaundice. The energy charge levels in the latter animals decreased even further after glucagon administration. Even though the energy consumption for gluconeogenesis after glucagon administration was limited in the jaundiced rabbits, it was sufficient to cause a deterioration in the hepatic energy balance. The above findings show that the administration of glucagon increases the amount of energy expended in the liver following a reduction in the hepatic energy charge in rabbits with obstructive jaundice. Therefore, even though glucagon has a choleretic effect, it should be administered carefully to patients with obstructive jaundice, especially in those with severe liver damage, such as in patients with cholangitis.

Adenine Nucleotides↗

Adult mesenchymal hamartoma of the liver mimicking bile duct cystadenoma.

We report a rare case of mesenchymal hamartoma in the cirrhotic liver of a 52-year-old Japanese male. The tumor, 3.5 cm in diameter, contained a cystic lesion and was located in the lateral segment. Bile duct cystadenoma was considered most likely preoperatively because of the patient's age and the normal levels of tumor markers. However, since malignancy of the lesion could not be ruled out by preoperative imaging diagnosis, lateral segmentectomy was performed. Histological examination led to a diagnosis of mesenchymal hamartoma, since the lesion consisted of a multilocular abnormal bile duct accompanied by abundant myxomatous or loose collagen.

Bile Duct Neoplasms↗

Visualisation of retinal blood flow by laser speckle flow-graphy.

A new method is demonstrated to visualise the microcirculation map of the human retina using a dynamic laser speckle effect. The retina is illuminated with a diode laser spot through a retinal camera, and its speckle image is detected by an area sensor. The output signal from the sensor is digitised, and the data for more than a hundred scannings of the speckle image are stored in a mass image memory. The difference between a pair of successive image data was calculated and integrated for each pixel. The results were displayed in colour graphics showing the spatial distribution of the blood flow in the retina.

Data Display↗

Ergostane glycosides from Petunia hybrida.

Six new ergostane glycosides, designated as petunioside A, petunioside B, 24-epipetunioside B, petunioside C, 24-epipetunioside C and petunioside D, were isolated from the methanolic extract of the fresh aerial parts of Petunia hybrida. Their structures were determined by means of spectroscopic analysis and single crystal X-ray analysis.

Carbohydrate Conformation↗

Protective efficacy in mice of post-exposure vaccination with vaccinia virus recombinant expressing either rabies virus glycoprotein or nucleoprotein.

Mice vaccinated intraperitoneally (i.p.) with 10(7) p.f.u. of a vaccinia virus recombinant expressing either the glycoprotein (rVac-G) or nucleoprotein (rVac-N) of rabies virus 3 weeks before challenge were protected against peripheral lethal infection. Similarly, by post-exposure vaccination in which mice were first infected with rabies virus and subsequently vaccinated i.p. with the recombinant, rVac-G conferred protection when given immediately following infection and up to 24 h after infection. Prior treatment of those mice with anti-CD8 monoclonal antibodies (MAb) did not significantly affect the outcome of the infection. In contrast, rVac-N failed to confer protection even with higher doses (10(8) p.f.u.) of the virus or even when administered by the intradermal route. Anti-nucleoprotein antibody production by these mice was not suppressed by prior rabies virus infection and the levels and the time of antibody production were similar to those of anti-glycoprotein antibody production in mice vaccinated with rVac-G after rabies virus infection. The cytotoxic T lymphocyte response was also not down-regulated by rabies virus in the mice that were given rVac-N. Possible mechanism(s) for the ineffectiveness of rVac-N by post-exposure vaccination in contrast to pre-exposure vaccination was discussed.

Animals↗

Target cells of cytotoxic T lymphocytes directed to the individual structural proteins of rabies virus.

Target cells of cytotoxic T lymphocytes (CTL) directed to the individual structural proteins (except for the large polymerase (L) protein) of rabies virus were established by expressing only the respective protein in murine neuroblastoma (NA) and murine macrophage (J774-1) cell lines. Mice infected with the ERA strain of rabies virus developed CTL responses to all of these rabies virus proteins. The cytotoxic activity was abrogated by pretreatment of the effector cells with anti-CD8 monoclonal antibody (MAb) and complement but not with anti-CD4 MAb. Cell lysis by CTL was blocked in the presence of anti-major histocompatibility complex (MHC) class 1 antibodies in J774-1 cell lines. Rabies virus-infected cells express these proteins at the surface, which can be recognized and lysed by the respective CTL. Mice immunized with beta-propiolactone-inactivated virus induced a CTL response against glycoprotein but not against internal viral components. This assay system might be useful for further analysis of the possible contribution of these proteins in the cell-mediated immune protection against rabies.

Animals↗

Inhibitory effect of recombinant fibronectin polypeptides on the adhesion of liver-metastatic lymphoma cells to hepatic sinusoidal endothelial cells and tumor invasion.

We have investigated the inhibitory mechanism of the initial arrest of L5178Y-ML25 lymphoma cells in a target organ (liver) by using recombinant fibronectin fragments with cell- and/or heparin-binding domains (C-274, H-271 or the fusion fragment CH-271). Pretreatment of hepatic sinusoidal endothelial (HSE) cell monolayers with lymphoma cells or their conditioned medium for 4 to 6 h resulted in the enhancement of lymphoma cell adhesion to HSE cell monolayer. The increased tumor adhesiveness was completely abolished by preincubation of the conditioned medium with anti interleukin-1 beta monoclonal antibody (mAb). Synthetic sialyl Le(x) (SLe(x)) as a ligand for endothelial cell leukocyte adhesion molecule-1 (ELAM-1) adhesion receptor and anti ELAM-1 mAb blocked the conditioned medium-induced enhancement of tumor-endothelial cell interaction, while pretreatment of the activated HSE cell monolayer with anti vascular cell adhesion molecule-1 (VCAM-1) mAb did not affect the enhanced tumor cell adhesion. These results indicate that tumor cell interaction with the stimulated HSE cells is mediated by ELAM-1 molecules on HSE cells. However, the expression of SLe(x) and SLe(a) on the tumor surface was not observed by flow cytometric analysis. ELAM-1-mediated enhancement of tumor cell adhesion to HSE monolayer was also inhibited in a concentration-dependent manner by CH-271 fusion polypeptide or the sulfated chitin derivative sulfated carboxymethyl-chitin, which can bind to the heparin-binding domain of CH-271. In addition, CH-271 inhibited not only tumor-endothelium interaction but also tumor cell invasion into reconstituted basement membrane Matrigel in vitro.

Animals↗

Defective natural killer (NK) cell-mediated cytotoxicity does not imply clonal involvement of NK cells in myelodysplastic syndromes.

The clonality of purified cells was examined in 10 myelodysplastic syndromes (MDS) patients by analysing the restriction fragment length polymorphism and methylation pattern of the phosphoglycerate-kinase gene. Natural killer (NK) cell-mediated cytotoxicity was also examined. The granulocytes and monocytes were monoclonal or oligoclonal in all cases, except for the monocytes in one case. Conversely, the NK and T cells had a polyclonal pattern in most cases, including all cases who had defective NK cell-mediated cytotoxicity. The hypothesis that reduced NK cell-mediated cytotoxicity in MDS is caused by a clonal involvement of NK cells was not supported by the present study.

Adult↗

Prognostic significance of loss of a chromosome 17p and p53 gene mutations in blast crisis of chronic myelogenous leukaemia.

In 31 cases of chronic myelogenous leukaemia (CML) we examined the prognostic significance of chromosomal loss of a 17p and p53 mutations at the onset of blast crisis (BC). p53 mutations were closely related to a shortened survival in CML-BC (P < 0.005 by the logrank test), whereas loss of a 17p by itself was not a poor prognostic indicator. The prognostic significance of loss of a 17p, however, emerged when combined with its predominance in the metaphases analysed. This predominance might easily and rapidly be screened by polymerase chain reaction-based analysis in about half of the cases.

Adolescent↗