Biomedical subjects

Y Fujii

Publications and source records attributed to Y Fujii.

At least 685 records · Page 38Linked to original sources

PubMed1993

[Development of oral reporting system in PACS environment].

An experimental radiologic reporting system using oral presentations has been developed and tested. The rewritable and compact magneto-optical disk (MOD) is employed to store oral diagnostic reports together with read radiologic images. The MOD is 5.25 inches in diameter, has a 600 MB memory capacity, and is erasable, light and compact. Advantages of the system are simultaneous retrieval of oral reports by a radiologist and the images he or she interpreted, and the capability of media circulation in addition to the function of filing. Thus MOD has a multimedia function of both off-line communication and filing. When medical images are interpreted and oral presentations are registered, automatically digitized oral reports and digitized images are filed in the MOD. Referring physicians can get oral diagnostic reports and can see the images at the same time on a personal computer. Furthermore, integration with voice recognition capability is being tried in our experiment.

Communication↗

PubMed1993

Characterization of CD4+ single positive cells that lack CD3 in the human thymus.

In the thymus of experimental animals, single positive cells that lack surface CD3 expression (CD3-CD4+CD8- or CD3-CD4-CD8+) have been reported to have intermediate characteristics between the CD4-CD8- cells and CD4+CD8+ cells. Here we show the presence of single positive cells in the human thymus that lack CD3 by means of three-color flow cytometric analysis. CD3- cells constitute 12 +/- 7.5% of CD4 single positive cells in 10 normal thymus samples. CD8 single positive cells, on the other hand, contained only 1.5 +/- 2.2% CD3- cells. Seventeen percent of these CD3-4+8- thymocytes were in S+G2/M phase, while only 4.3% of CD4+CD8- thymocytes were in S+G2/M. The surface antigen phenotype of CD3-CD4+CD8- thymocytes was CD1(low), CD2+, alpha beta TCR-, CD29(high), LFA-1+, ICAM-1-, IL-2R-, CD45common (low), CD45RA-, and CD45R0(low). They expressed cytoplasmic CD3+ and 28% of them expressed cytoplasmic CD3 and cytoplasmic alpha beta TCR. The levels of CD2, CD29, CD45R0, cytoplasmic CD3, and cytoplasmic alpha beta TCR expression were intermediate between the CD3-4-8- and CD4+8+ populations. These results indicate that CD3-CD4+CD8- thymocytes constitute a minor but significant population in the human thymus. Their surface antigen phenotype and the high incidence of dividing cells suggest that they are immature and probably on their way to the CD4+8+ double positive thymocytes.

Adolescent↗

PubMed1993

Functional expression of human P-glycoprotein in Schizosaccharomyces pombe.

Human MDR1 cDNA was introduced into the human cultured cells KB-3-1 and Schizosaccharomyces pombe pmd1 null mutant KN3. The drug sensitivity of KB-G2 and KN3/pgp, expressing human P-glycoprotein, was examined. KB-G2 was resistant to the peptide antibiotics valinomycin and gramicidin D as well as having a typical multidrug resistance (MDR) phenotype. KN3/pgp was resistant to valinomycin and actinomycin D, but not to adriamycin. The ATP-hydrolysis-deficient mutant did not confer KN3 resistance to these antibiotics. Human P-glycoprotein expressed in S. pombe seemed to lack N-glycosylation. The N-glycosylation-deficient mutant, however, conferred a typical MDR phenotype on KB-3-1. These results suggest that human P-glycoprotein functions as an efflux pump of valinomycin and actinomycin D in the membrane of S. pombe.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1993

Aggressive pulmonary metastasectomy for soft tissue sarcomas.

BACKGROUND: To evaluate the efficacy of aggressive pulmonary metastasectomy for treating soft tissue sarcomas, the clinical data on the surgical management of 23 patients with extensive pulmonary metastases from soft tissue sarcomas were reviewed. METHODS: Between January 1973 and April 1991, 9 male patients and 14 female patients were treated. Their ages ranged from 13-68 years (median, 42 years). Twenty-one patients (91%) had bilateral and multiple metastases, and two patients had solitary metastasis. The number of resected metastatic nodules ranged from 1-110 (mean, 30.5). As an initial surgical approach, median sternotomy was used on 18 patients and lateral thoracotomy on 5 patients. Eleven patients underwent two or more explorations for recurrent metastases using lateral thoracotomy. The neodymium:yttrium-aluminum-garnet (Nd:YAG) laser was adopted in 10 patients since 1986. RESULTS: The actuarial 2-year and 5-year survival rates after the first pulmonary resection were 49.7% and 24.8%, respectively. Histologic type (alveolar soft part sarcoma versus synovial sarcoma, P < 0.025), histologic grade (G1 and G2 versus G3, P < 0.01), and metastatic localization (subpleural versus extrapleural, P < 0.005) were the most significant prognostic factors for aggressive pulmonary metastasectomy of soft tissue sarcomas. Application of laser surgery, absence of local recurrences, and absence of extrapulmonary metastases before pulmonary resection also correlated with better prognosis with borderline significance. CONCLUSIONS: Aggressive pulmonary metastasectomy for soft tissue sarcomas is a recommended procedure, even in the case of extensive metastases. The combination of median sternotomy and Nd:YAG laser-assisted surgery is a useful technique, especially in bilateral multiple pulmonary metastases.

Adolescent↗

PubMed1993

Expression of the gene for nerve growth factor (NGF) in the monkey central nervous system.

The expression of the gene for nerve growth factor (NGF) was examined in the central nervous system of adult and fetal monkeys. In adults, the highest level of NGF mRNA was found in the hippocampus and relatively high levels were observed in the cerebral cortices and thalamus. NGF mRNA was also detected in the cerebellum and the caudate nucleus. In the spinal cord, there was no evidence of the mRNA. The levels of NGF mRNA were closely correlated with those of NGF. At embryonic day 140 (E140), levels of NGF mRNA in the visual cortex and cerebellum were three times higher than those at the adult stage. Our previous study on the ontogeny of NGF (Hayashi, M. et al., Neuroscience, 36 (1990) 683-689) showed that the level of NGF in the visual cortex at E140 is the same as that at adult stage. Thus, at the fetal stage, NGF may be actively transported from the cerebral cortex to other regions of the brain, such as the basal forebrain area. By contrast, the levels of NGF and NGF mRNA in the cerebellum were almost the same at the adult and fetal stages, suggesting that NGF, which is synthesized in the cerebellum, may be taken up locally by cerebellar cells.

Animals↗

PubMed1993

Production of heat-stable enterotoxin II by chicken clinical isolates of Escherichia coli.

Enterotoxigenic Escherichia coli isolated from diarrhea stools of chickens were examined for production of heat-stable enterotoxin II which is considered to be implicated only in diarrhea of pigs. Seven out of 38 strains examined were found to contain heat-stable enterotoxin II gene, determined by colony hybridization and the polymerase chain reaction. The culture supernatants of these strains caused fluid accumulation in the mouse intestinal loop test. This fluid accumulation activity was not lost by heating at 100 degrees C and was neutralized by anti-heat-stable enterotoxin II antiserum. Purified heat-stable enterotoxin II caused fluid accumulation in the chicken intestinal loop assay. These results indicate that STII-producing E. coli is implicated in chicken diarrhea.

Animals↗

PubMed1993

Both CD45RA+ and CD45RA- subpopulations of CD8+ T cells contain cells with high levels of lymphocyte function-associated antigen-1 expression, a phenotype of primed T cells.

Expression of CD45 isoforms and some adhesion molecules on T cells change during T cell activation. In CD4+ T cells, it has been reported that CD45RA is lost and CD45RO is up-regulated when CD4+ T cells are stimulated. This change seemed to be irreversible and thus CD45RA may serve as a marker for virgin T cells and CD45R0 as a marker for memory T cells in CD4+ T cells. In CD8+ T cells, however, the expression of CD45 isoform has been less well understood. We have previously reported the switching of CD45 isoform expression may be reversible and CD8+CD45RA+ T cells may contain preactivated T cells. We present further evidence to support this notion by investigating the expression of lymphocyte function-associated Ag (LFA-1) in relation to CD45 isoform expression in various T cell populations in the human. In the thymus and umbilical cord blood, more than 97% of both CD4+ and CD8+ single positive T cells expressed LFA-1 at a low level. In CD4+ peripheral blood T cells, a high level of LFA-1 expression was found only in the CD45RA- population: 98% of CD45RA+ cells were LFA-1low. In CD8+ peripheral blood T cells, in contrast, a distinct population of LFA-1high cells was found in CD45RA+ subset, comprising about 45% of this subset in a 32-yr-old donor. In 7 days after stimulation with PHA, all CD4+ and CD8+ T cells, irrespective of their CD45 isoform expression, were LFA-1high. The proportion of CD45RA+ cells decreased in CD4+ but slightly increased in CD8+ T cells after the stimulation. These results support the notion that CD45RA and CD45R0 mark virgin and memory T cells respectively in the CD4+ T cells, and that CD8+CD45RA- T cells are primed. However, the validity of CD45RA as a marker of virgin cells in CD8+ T cells is seriously questioned.

Adult↗

PubMed1993

Age-related accumulation of LFA-1high cells in a CD8+CD45RAhigh T cell population.

The differential expression of CD45 isoforms has been suggested as a marker for stages of post-thymic T cell development, that is, CD45RA+CD45R0-T cells and CD45RA-CD45R0+ T cells are supposed to be virgin and memory cells respectively. Recently, several adhesion molecules have been shown to be up-regulated on the cell surface of memory T cells, and have been suggested to serve as a memory marker. In this study, we investigated the levels of LFA-1 expression on T cells in various subpopulations defined by CD45 isoform expression in donors of various ages. In CD4+ T cells, the proportion of LFA-1high cells among CD45RAhighCD45R0- T cells remained low in all age groups and did not show significant accumulation with age. CD4+CD45RA-CD45R0high T cells expressed LFA-1 at a higher level than CD4+CD45RAhighCD45R0- T cells. Thus, the currently prevailing view that CD45RA and CD45R0 can be markers for virgin and primed cells was consistent with LFA-1 expression in CD4+ T cell population. In CD8+ T cells, however, CD45RAhighCD45R0- T cells consisted of two distinct subpopulations, LFA-1low and LFA-1high cells, whereas CD45RA-CD45R0high T cells were almost exclusively LFA-1high. When CD29 expression was examined in place of LFA-1 expression, similar results were obtained; CD45RAhigh CD45R0- T cells consisted of two distinct subpopulations, CD29-to low and CD29high cells, while CD45RA-CD45R0high T cells were mostly CD29high. The proportion of LFA-1high cells in the CD8+CD45RAhigh T cell subpopulation increased significantly as a function of age (r = 0.9, p < 0.001). It ranged from 8% in a 14-year-old donor to 94% in a 79-year-old donor. Furthermore, the proportion of CD8+CD45RAhighLFA-1high cells in the CD8+ T cell population increased significantly as a function of age (r = 0.85, p < 0.001). On the other hand the proportion of LFA-1high cells in CD8+CD45RA- T cell subpopulation exceeded 90% in most donors irrespective of age. These results indicate that the CD8+CD45RAhighCD45R0- T cell subpopulation contains a considerable number of LFA-1high cells and CD29high cells, phenotypically similar to previously activated cells. Thus, in terms of LFA-1 and CD29 expressions, the simple scheme that CD45RA is a marker of virgin cells is not applicable to the CD8+ T cell population.

Adolescent↗

PubMed1993

Identification of alpha-fetoprotein-P4 sugar chain as alpha 2-->6 monosialylated biantennary complex-type oligosaccharides with an exposed galactose on the mannose alpha 1-->6 arm by two-dimensional extended agarose gel-lectin affinity electrophoresis.

Erythroagglutinating phytohemagglutinin (E-PHA)-reactive alpha-fetoprotein (AFP)-P4 and E-PHA weakly-reactive AFP-P3 of sera from cord blood at term and from patients with hepatocellular carcinomas showed a mobility of monosialo-AFP in two-dimensional extended agarose gel-E-PHA affinity electrophoresis. Asialo-AFP had as high an affinity for E-PHA as that of monosialo-AFP-P4, while disialo-AFP, AFP-P2, revealed a negligible affinity for E-PHA. For Allomyrina dichotoma lectin (allo A), asialo-AFP had no affinity with a mobility of AFP-A1s, monosialo-AFP-P4 had the highest affinity with a mobility of AFP-A3, and monosialo-AFP-P3 had an intermediate affinity with a mobility of AFP-A2s. The affinity of AFP-P4 for E-PHA was reduced by galactosidase digestion, indicating the presence of galactose residues, one sialylated and the other exposed.(ABSTRACT TRUNCATED AT 250 WORDS)

Carbohydrate Conformation↗

PubMed1993

Characterization of E-PHA-reactive alpha-fetoprotein isoforms by two-dimensional lectin affinity electrophoresis.

Erythroagglutinating phytohemagglutinin (E-PHA)-dependent isoforms of human alpha-fetoprotein (AFP) from cord blood were analyzed for their carbohydrate structures by two-dimensional electrophoresis with E-PHA combined with extended agarose gel electrophoresis or with affinity electrophoresis with concanavalin A or Allomyrina dichtoma lectin. By means of neuraminidase and/or beta-galactosidase treatment, AFP-P2 was identified as alpha 2-->6 disialo-AFP, AFP-P3 as having biantennary structures with alpha 2-->6 monosialylated galactose of the Mannose (Man) alpha 1-->6 arm, AFP-P4 as having alpha 2-->6 monosialylated galactose of the Man alpha 1-->3 arm, and AFP-P5 as disialo-AFP with alpha 2-->3 sialylated galactose of the Man alpha 1-->6 antenna with the alpha 2-->6 sialylated galactose of the other antenna. Desialylated AFP with the terminal galactose of the Man alpha 1-->6 antenna with or without the galactose of the other arm also had a migration of AFP-P4, and other hydrolytic intermediates without the terminal galactose of the Man alpha 1-->6 arm with and without the galactose of the other antenna had mobilities of AFP-P3s and AFP-P3, respectively. Thus, the present system of two-dimensional lectin affinity electrophoreses would provide a model for the determination of the sugar chain structure of glycoproteins.

Carbohydrate Conformation↗

PubMed1993

Regulation of antibody production by helper T cell clones in experimental autoimmune myasthenia gravis is mediated by IL-4 and antigen-specific T cell factors.

Acetylcholine receptor (AChR)-specific rat T cell clones (CD4+, CD8-, and OX22-) were shown to secrete both Th1 and Th2 lymphokines, IL-2, IL-4, and IFN-gamma following stimulation with AChR. These clones helped production of antibody to AChR by B cells which was found to be regulated primarily by IL-4, not by IL-2, secreted by the T cells in response to AChR. Cell-free supernatants from some AChR-activated T cell clones led to production of low levels of antibody to AChR by B cell-enriched, AChR-primed lymph node cells. Supernatant-regulated help in antibody production by B cells was antigen specific, and antibodies to T cell receptors blocked the antigen-specific activity. Thus, supernatant-mediated help may not be due solely to IL-4, and other factors, possibly including some fragment of the T cell antigen receptor present in the supernatant, appear to contribute to helping antibody production by B cells.

Animals↗

PubMed1993

Histochemical demonstration of copper in LEC rat liver.

Livers of LEC rats were histochemically stained for copper according to the modified Timm's method, which includes trichloroacetic acid (TCA) treatment. TCA pretreatment was effective in removing zinc and iron, leaving as the major metal in the liver. Hepatocytes in 3-month-old rats were stained intensely by the modified Timm's method, both in frozen sections and in paraffin-embedded specimens. The centrilobular hepatocytes were usually stained, but positive cells were also randomly distributed in the hepatic lobes, showing a mosaic pattern. The staining was intensified in 8- compared to 3-month-old LEC rats. In contrast hepatocytes from LEA rats, the normal counterpart of LEC rats, were faintly stained for copper. Proliferating cholangioles found in older LEC rats were shown to lack copper deposition, and hepatocellular carcinoma showed less copper deposits than the hepatocytes surrounding the tumor. The copper staining was augmented in livers of LEC rats subjected to copper-loading, but was less intense in the livers treated with D-penicillamine. The staining intensity under the various experimental conditions showed good correlation with the copper concentration. Lysosomal deposition of copper in hepatocytes was demonstrated by electron microscopic analysis for copper. Thus the modified Timm's method was shown to produce valuable results in demonstrating copper in LEC rat livers, providing important information for an understanding of the mechanism of copper deposition and hepatic disease of the animal.

Animals↗

PubMed1993

Neuronal pp60c-src(+) in the developing chick spinal cord as revealed with anti-hexapeptide antibody.

Polyclonal antibody was raised in rabbits against a synthetic hexapeptide R-K-V-D-V-R corresponding to a unique amino acid sequence of the neuron-specific c-src gene product pp60c-src(+). The antibody was purified by affinity chromatography. A single band with an apparent molecular mass of 60 kDa was recognized when the supernatant of homogenates of brain and spinal cord from chick embryos and chicks was probed with the affinity purified anti-hexapeptide antibody after SDS-polyacrylamide gel electrophoresis followed by Western blotting. Specificity of the antibody was further characterized by autophosphorylation assay of immunoprecipitate in comparison with the monoclonal antibody 327. Immunocytochemical studies by light microscopy revealed that pp60c-src(+) was localized in flake-like aggregates in neuronal cell bodies of the spinal cord in 7-15-day-incubated chick embryos and newly hatched chicks. Developing spinal ganglia and muscle cells were also immunoreactive at early developmental stages. By electron microscopy, the reaction product was observed mainly in two regions. One region was at polysomes and along the membranes of the rough endoplasmic reticulum. The other region was along the neuronal plasma membrane--at subsurface cisterns and at synapses. At synapses, the postsynaptic density, presynaptic membrane and synaptic vesicle membranes were immunostained. Immunoreactivity at synapses were more frequently observed at earlier stages than at later stages of development. These findings suggest that pp60c-src(+) is actively produced in developing neurons and has some important roles in synaptogenesis. In mature synapses, pp60c-src(+) may be involved in the interaction of synaptic vesicles with the presynaptic membrane.

Amino Acid Sequence↗

PubMed1993

Immunocytochemical study of membrane skeletons in abnormally shaped erythrocytes as revealed by a quick-freezing and deep-etching method.

Ultrastructures of membrane skeletons in spherocytic and elliptocytic erythrocytes were investigated immunocytochemically. Erythrocytes obtained from patients with hereditary spherocytosis (HS) and hereditary elliptocytosis (HE) were split open mechanically to obtain exposed cytoplasmic sides of erythrocyte membranes and were immunostained with anti-spectrin antibody. Replica membranes were prepared by a quick-freezing and deep-etching method and were checked by electron microscopy. The in situ membrane skeletons of normal erythrocytes consisted mainly of reticular patterns of spectrin filaments, which formed networks on the cytoplasmic sides of the cell membrane. In contrast, the membrane skeletons of abnormally shaped erythrocytes (HS and HE) were much less filamentous and more granular than those of normal erythrocytes. This abnormal organization in erythrocyte membrane skeletons may be one of the factors that induce abnormally shaped erythrocytes in HS and HE patients.

Adult↗

PubMed1993

Calcium supplementation in osteoporosis.

Although calcium is the most abundant inorganic constituent of the bone, indispensable for the maintenance of its physical strength, the role of calcium nutrition in the development of osteoporosis and the preventive and therapeutic significance of calcium supplementation in osteoporosis have been matters of intense controversy. The wide difference in the baseline nutritional intake of calcium among different groups and the variation in age of the patients studied may have been contributory factors. Emphasis has so far been placed on the rapid bone loss in the immediate postmenopausal period predominantly influenced by estrogen deficiency which has overshadowed the effect of calcium. The strong dependence of the effect of calcium preparation used tends to be forgotten. In the present study employing oyster shell electrolysate as the calcium source in patients with a mean age of approximately 80 years, bone mineral density was kept significantly higher than in age-matched, non-supplemented patients over a period of 2 years. In separate experimental studies, rats maintained on 2% calcium showed higher bone mineral content and lived longer than did controls maintained on 1% calcium. Age-associated deterioration of renal function and hyperlipidemia were also prevented by calcium supplementation.

Aged↗

PubMed1993

Contractility of fatigued diaphragm is improved by dobutamine.

The effects of dobutamine (DOB) on diaphragmatic fatigue were examined in 20 anaesthetized, mechanically ventilated dogs. Animals were divided into two groups: the DOB group (n = 10) and the control group (n = 10). Diaphragmatic fatigue was induced by intermittent supramaximal electric stimulation applied to bilateral phrenic nerves at a frequency of 20 Hz for 30 min. Diaphragmatic contractility was assessed with transdiaphragmatic pressure (Pdi). After diaphragmatic fatigue, Pdi decreased at low-frequency (20 Hz) stimulation (P < 0.05), whereas the decrease was minimal at high-frequency (100 Hz) stimulation. In the DOB group, after producing fatigue, the continuous administration of 10 micrograms.kg-1.min-1 dobutamine iv for 30 min produced an increased Pdi at both frequencies of stimulation (P < 0.05). The Pdi returned to pre-fatigue values after cessation of dobutamine administration. In the control group, the speed of recovery from fatigue was much slower at low-frequency stimulation. The integrated diaphragmatic electric activity (Edi) in the two groups did not change throughout the experiment at any frequency of stimulation. We conclude that dobutamine improves contractility in fatigued diaphragm.

Animals↗

PubMed1993

Role of systematic mediastinal dissection in N2 non-small cell lung cancer patients.

The surgical results in patients with non-small cell lung cancer staged as N2 disease were historically analyzed. Twenty-six patients were confirmed to have N2 disease on the basis of histologic study of suspicious nodes without systematic mediastinal dissection (PI group), 50 patients underwent systematic mediastinal dissection (R2 group), and 17 patients had bilateral mediastinal dissection, 4 of whom were N3 positive (R3+ group) and 13, N3 negative (R3- group). The difference in the 5-year survival rate between the PI and R2 groups (8% and 16.3%, respectively) was not significant. All 4 patients in the R3+ group died of recurrence within 14 months after operation. Several findings suggest that some patients with N2 disease, especially those with three or more N2-positive stations, actually have N3 disease: The 3-year survival rate was higher in the R3- group (51.3%) compared with the R2 (32.6%; p = not significant) and PI groups (24%; p = 0.01); in the R2 group, the survival rate was significantly (p = 0.017) better for patients with N2 metastases in two stations or less than in patients with three or more N2-positive stations; and the rate of early postoperative death related to cancer correlated with the number of N2-positive stations. We conclude that accurate diagnosis of N2 and N3 disease, and therefore better evaluation of survival for patients with N2 disease, is possible by bilateral mediastinal dissection.

Aged↗

PubMed1993

Enhancement of systemic and mucosal immune responses following oral administration of liposomes.

The effects of liposomes on the systemic and mucosal immune response were investigated using bovine serum albumin (BSA) in BALB/c mice. Following three oral administrations of varied formulations at 1-week intervals, serum BSA-specific IgG levels were increased significantly by BSA encapsulated in liposomes and moderately by a mixture of liposomes and BSA. Serum and salivary BSA-specific IgA levels were elevated by BSA-encapsulating liposomes only. Liposomes thus activate not only the systemic immune response but also the mucosal immune response following their oral administration. However, no increase in salivary IgA levels was observed by intraperitoneal or subcutaneous injection of BSA-encapsulating liposomes. The production of IgA is closely related to the oral administration of liposomes encapsulating antigens. Liposomes thus function as carriers of oral vaccines against various infections of the mucosal surface.

Administration, Oral↗