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Biomedical subjects

S Matsuda

Publications and source records attributed to S Matsuda.

At least 181 records · Page 10Linked to original sources
PubMed1999

No beneficial effect from addition of etoposide to daunorubicin, cytarabine, and 6-mercaptopurine in individualized induction therapy of adult acute myeloid leukemia: the JALSG-AML92 study. Japan Adult Leukemia Study Group.

To assess the efficacy of etoposide added to the standard remission induction therapy for acute myeloid leukemia (AML), newly diagnosed adult AML patients were randomized to receive either daunorubicin (40 mg/m2/day x 4 or more), behenoyl cytarabine (200 mg/m2/day x 10 or more), and 6-mercaptopurine (70 mg/m2/day x 10 or more) (BHAC-DM), or the same three drugs plus etoposide (100 mg/m2/day x 5) (BHAC-EDM) for response-oriented individualized induction therapy. The patients achieving complete remission (CR) received the same 3 courses of consolidation therapy followed by 6 courses of maintenance/intensification therapy. M3 patients were excluded because all-trans retinoic acid was used. Of 667 patients registered, 655 were evaluable. The median age was 49 (range 15 to 85). CR rates were 77% in the BHAC-DM group and 75% in the BHAC-EDM group. In 173 M4 patients, CR rates were 86% and 69% (P = 0.009), and in 32 M5 patients, 80% and 77% (P = 0.810) in the BHAC-DM and the BHAC-EDM groups, respectively. The predicted 6-year overall survival rates were 30% and 38% (P = 0.925) for the BHAC-DM and BHAC-EDM groups, and the disease-free survival rates of CR patients were 25% and 35% (P = 0.352), respectively. Nonhematological toxicities after the first course of induction therapy were almost equal among the two groups, with the exception of a greater loss of hair (P = 0.024) and more frequent diarrhea (P = 0.013) in the BHAC-EDM group. We concluded that in the present study, the addition of etoposide to the standard individualized induction therapy showed no advantage in adult AML, even among M4 and M5 patients.

Acute Disease↗
PubMed1999

Limited efficacy of magnesium for the treatment of variant angina.

Some patients with variant angina show both ST segment elevation at rest and exercise-induced ST segment elevation. Magnesium deficiency has also been observed in patients with variant angina. This study investigated the correlation between the degree of magnesium deficiency and the efficacy of intravenous administration of magnesium in patients with variant angina. Fifteen patients with angiographically confirmed variant angina were assessed for magnesium deficiency and whether intravenous administration of magnesium (19.2 mEq/l) suppressed exercise-induced ST segment elevation. All 15 patients were studied with a magnesium retention test (0.2 mEq/kg over 4 hr) to analyze magnesium deficiency. In our study, magnesium retention rate in patients with variant angina was not higher than that of controls (57 +/- 24% vs 45 +/- 10%, NS). All 15 patients had anginal attacks during accelerated exercise combined with hyperventilation after placebo infusion, whereas only 8 patients had anginal attacks after magnesium administration. ST segment elevation occurred in 14 patients after placebo infusion, but in only 4 patients after magnesium administration. There were no correlations between disease activity, degree of magnesium deficiency or failure of suppression of ST elevation by the intravenous administration of magnesium. Intravenous administration of magnesium can suppress exercise-induced coronary spasms in some patients with variant angina, but the degree of magnesium deficiency did not correlate with the suppressions of exercise-induced ST elevation after magnesium administration. Intravenous administration of magnesium had limited efficacy in patients with variant angina and exercise-induced ST segment elevation.

Acetylcholine↗
PubMed1999

[Clinical evaluation of biapenem in various infectious diseases].

The clinical usefulness of injectable biapenem (BIPM) was examined for various infectious diseases in the fields of internal medicine, urology, surgery, orthopedics, obstetrics and gynecology, otorhinolaryngology, ophthalmology, dermatology, oral surgery, and plastic surgery. BIPM was administered by intravenous drip infusion at a dose of 150, 300, or 600 mg twice a day. The concentrations in various body fluid and tissues were also examined. 1. In the total enrollment of 256 cases, the numbers subjected to the analyses for clinical efficacy, bacteriological efficacy, side effects and abnormal laboratory findings were 214, 170, 252 and 251 cases, respectively. 2. The clinical efficacy rate was 85.5% (183/214 cases) as a whole, being 2/2 for sepsis, 6/8 for cellulitis and lymphangitis, 76.2% (16/21) for traumatic, operative wound and burn infections, 4/6 for osteomyelitis and arthritis, 92.9% (13/14) for peritonsillar abscess and peritonsillitis, 83.3% (15/18) for chronic lower respiratory tract infection, 7/7 for pneumonia, 83.3% (30/36) for complicated urinary tract infection, 100% (14/14) for cholecystitis and cholangitis, 88.2% (15/17) for peritonitis, 86.5% (32/37) for internal genital infection, 8/9 for pelvic peritonitis, 2/4 for corneal ulcer, orbital infection and panophthalmitis, 1/2 for otitis media, 4/4 for sinustitis, 93.3% (14/15) for osteitis of jaw and cellulitis of mouth floor. The efficacy rate in the poor responders to the pretreatment by other antibiotics was 86.4% (70/81). 3. 300 strains of causative organisms were isolated from 170 cases which contained polymicrobial infections. The elimination rate of causative organisms was 85.3% (256/300 strains), in terms of bacteriological efficacy. 4. Side effects were noted in 11 of 252 cases (4.4%) with 11 events. The signs and symptoms were the skin symptoms (5 cases), gastro-intestinal symptoms (3 cases), interstitial pneumonia (2 cases), and feeling bad (1 case), all of which disappeared during treatment or after the discontinuation of treatment. The abnormal laboratory findings were observed in 31 of 251 cases (12.4%) with 50 events, and major ones were an increase in eosinophils, and elevations of AST, ALT, gamma-GTP and Al-p. 5. The concentrations of BIPM in body fluid and tissues were determined in 46 cases (212 samples) most of which were administered 300 mg of BIPM by intravenous drip infusion for 60 minutes. The concentrations in the sputum within 6 hours after administration were 0.1-2.5 micrograms/g. The maximum concentrations in body fluid and tissues were 0.2-1.8 micrograms/g or ml in the bile, middle ear mucosa, tonsillar tissue, aqueous humor and bone tissues and were 2.0-5.7 micrograms/g or ml in the gallbladder, maxillary sinus mucous membrane, ethmoidal sinus mucous membrane, oral tissues, skin, woman genitals, synovia, joint tissue, and the eschar. The concentrations in the uterine arterial plasma and retroperitoneal fluid were almost similar to those in the cubitl vein plasma. From the above-mentioned results of clinical efficacy, bacteriological efficacy, and safety, injectable BIPM was confirmed to be useful in the treatment of moderate, severe and/or refractory infections in various fields.

Adult↗
PubMed1999

Digital kids of the Heisei era: experiment at Toyonaka Bunka Kindergarten.

I wonder what most people think when they hear of small children playing on computers in kindergarten. One can almost hear the responses: "Why should kindergarten children have to use computers?" Small children are using computers? It's much too earlyl" "At kindergarten children should be singing, playing games, and making mud pies!" A computer is the epitome of the artificial. If we really make a mess of things, humans will become slaves to computers. What can they be thinking, putting such things in kindergartens as a child's toy? Many people who think in this way have never touched a computer, and it often seems the case that these "emotional opponents" are opposed to them only because of their own preconceptions. There is still a preconception that" a computer = a square machine like a TV with lots of difficult-looking keys". Computers are now in virtually all of the electronic appliances we use every day, refrigerators, washing machines, vacuums and televisions, and we think nothing of it. We live each day using computers, but only the "square" computer invites such contempt. Why is this the case? On the other side, there are the "proactive endorsers", who think "Computers have spread thus far in society and schools, so we must let children become familiar with them from a very young age!" These people often seem to want to teach everyone everything. There is much to know about the image and use of computers. They seem to think that if adults don't teach them, children won't understand anything. On this point, they are at the same level as the "emotional opponents", in that they conceive of computers as being something out of the ordinary.

Adult↗
PubMed1998

Pneumoconiosis problem among the Vietnamese coal mine workers.

In this report, the authors present the pneumoconiosis problem among Vietnamese coal mine workers. As coal is one of the most important products for export, its production has been intensified recently. With the strong incentive for rapid economic development, health problems of miners tend to take second place. As shown in the present report, miners' working conditions are very bad, and health protection measures are not sufficiently implemented. It is apparent that official statistics underestimate the actual situation because of the inadequacy of the reporting system. Because the financial barrier to establishing a sufficient reporting system for pneumoconiosis is enormous, an epidemiologic study is the most effective way to assess the actual situation. It is also useful to conduct epidemiologic studies as part of an international collaborative project, in order to transfer necessary knowledge and epidemiologic skills from the developed countries to Vietnam.

Coal Mining↗
PubMed1998

Atypical protein kinase Clambda binds and regulates p70 S6 kinase.

p70 S6 kinase (p70 S6K) has been implicated in the regulation of cell cycle progression. However, the mechanism of its activation is not fully understood. In the present work, evidence is provided that an atypical protein kinase C (PKC) isotype, PKClambda, is indispensable, but not sufficient, for the activation of p70 S6K. Both the regulatory and kinase domains of PKClambda associate directly with p70 S6K. Overexpression of the kinase domain without kinase activity or the regulatory domain of PKClambda results in the suppression of the serum-induced activation of p70 S6K. In addition, two types of dominant-negative mutants of PKClambda, as well as a kinase-deficient mutant of p70 S6K, suppress serum-induced DNA synthesis and E2F activation. The overexpresion of the active form of PKClambda, however, fails to activate p70 S6K. These results suggest that PKClambda is a mediator in the regulation of p70 S6K activity and plays an important role in cell cycle progression.

Amino Acid Sequence↗
PubMed1998

[AHP analysis of activities expected of public health nurses at a public health center].

The activities expected of Public Health Nurses (PHN) at a Public Health Center (PHC) were evaluated by the AHP technique based on the results of a Focus Group Discussion among 7 PHNs working in K PHC, Fukuoka. Among the five PHN activities, "Collection and analysis of information" was evaluated as the most important, followed by "Consultation", "Coordination of different sectors", "Control and support of patients with chronic diseases", and "Health education for the public". However, the investigated PHNs concluded that their knowledge of and skill in doing "Collection and analysis of information" are insufficient. It is therefore recommended that continuous training courses on statistics and epidemiology be organized for the PHNs.

Decision Making↗
PubMed1998

[A plan of the life-long learning support system of UOEH--possibility for the introduction of distance learning system by the Internet].

In order to keep up with the rapid advance in knowledge and skills in various industrial sectors, the needs for the life-long learning has increased recently. This is also the case for the University of Occupational and Environmental Health, Japan, which has as its aim the education of occupational health specialists. In fact, there are many universities and colleges which have organized some post-graduate courses for the workers. However, most of these courses are for workers who can come to classes in the daytime or evening. In the case of UOEH, it is not enough to organize such type of classes in order to respond to the social needs, because it has to offer an opportunity of life-long learning for all occupational health specialists in all parts of Japan. In order to solve this problem, it is recommended that a distance learning system based on modern information technology such as the internet be organized. In this report, the authors present the distance learning system of Wisconsin University in the USA, and that of Tamagawa Gakuen University of Japan. After evaluating these two systems, a plan for a life-long learning support system of UOEH is suggested, which consists of a distance learning system based on the internet.

Education, Continuing↗
PubMed1998

Interleukin 3 prevents delayed neuronal death in the hippocampal CA1 field.

In the central nervous system, interleukin (IL)-3 has been shown to exert a trophic action only on septal cholinergic neurons in vitro and in vivo, but a widespread distribution of IL-3 receptor (IL-3R) in the brain does not conform to such a selective central action of the ligand. Moreover, the mechanism(s) underlying the neurotrophic action of IL-3 has not been elucidated, although an erythroleukemic cell line is known to enter apoptosis after IL-3 starvation possibly due to a rapid decrease in Bcl-2 expression. This in vivo study focused on whether IL-3 rescued noncholinergic hippocampal neurons from lethal ischemic damage by modulating the expression of Bcl-xL, a Bcl-2 family protein produced in the mature brain. 7-d IL-3 infusion into the lateral ventricle of gerbils with transient forebrain ischemia prevented significantly hippocampal CA1 neuron death and ischemia-induced learning disability. TUNEL (terminal deoxynucleotidyltransferase-mediated 2'-deoxyuridine 5'-triphosphate-biotin nick end labeling) staining revealed that IL-3 infusion caused a significant reduction in the number of CA1 neurons exhibiting DNA fragmentation 7 d after ischemia. The neuroprotective action of IL-3 appeared to be mediated by a postischemic transient upregulation of the IL-3R alpha subunit in the hippocampal CA1 field where IL-3Ralpha was barely detectable under normal conditions. In situ hybridization histochemistry and immunoblot analysis demonstrated that Bcl-xL mRNA expression, even though upregulated transiently in CA1 pyramidal neurons after ischemia, did not lead to the production of Bcl-xL protein in ischemic gerbils infused with vehicle. However, IL-3 infusion prevented the decrease in Bcl-xL protein expression in the CA1 field of ischemic gerbils. Subsequent in vitro experiments showed that IL-3 induced the expression of Bcl-xL mRNA and protein in cultured neurons with IL-3Ralpha and attenuated neuronal damage caused by a free radical-producing agent FeSO4. These findings suggest that IL-3 prevents delayed neuronal death in the hippocampal CA1 field through a receptor-mediated expression of Bcl-xL protein, which is known to facilitate neuron survival. Since IL-3Ralpha in the hippocampal CA1 region, even though upregulated in response to ischemic insult, is much less intensely expressed than that in the CA3 region tolerant to ischemia, the paucity of IL-3R interacting with the ligand may account for the vulnerability of CA1 neurons to ischemia.

Animals↗
PubMed1998

The role of calcium-binding sites in S-modulin function.

S-modulin controls rhodopsin phosphorylation in a calcium-dependent manner, and it has been suggested that it modulates the light sensitivity of the photoreceptor cell. S-modulin binds to the ROS membrane at high Ca2+ concentration, and N-terminal myristoylation is necessary for this property (the calcium-myristoyl switch). S-modulin has four EF-hand motifs, of which two (EF-2 and -3) are functional. Here, we report on the roles of EF-2 and -3 in S-modulin function (calcium binding, membrane association, and inhibition of rhodopsin phosphorylation) by site-directed mutants (E85M and E121M). Surprisingly, E121M, which has a mutation in EF-3, neither binds Ca2+ nor inhibits phosphorylation. In contrast, E85M binds one Ca2+ and has the same membrane affinity as wild-type S-modulin, but has lost the ability to inhibit rhodopsin phosphorylation. It is suggested that the binding of Ca2+ to EF-3 is probably required for EF-2 to be a functional Ca2+-binding site and to induce exposure of the myristoyl group; and that the binding of Ca2+ to EF-2 is important for the interaction with rhodopsin kinase.

Binding Sites↗
PubMed1998

Toroidal coil counter-current chromatography. Achievement of high resolution by optimizing flow-rate, rotation speed, sample volume and tube length.

This paper deals with optimization of a new seal-free compact toroidal coil centrifuge to achieve high resolution in analytical counter-current chromatography (CCC). Toroidal coil CCC (hydrostatic motion) has advantages compared with high-speed CCC (efficiently mixing solution with planetary motion) in the separation of protein or easily emulsified samples. A toroidal coil separation column of 0.4 mm I.D. PTFE tubing was accommodated around the periphery of the cylindrical centrifuge bowl. Using a two-phase solvent system composed of chloroform-acetic acid-0.1 M hydrochloric acid (2:2:1, v/v/v) and a set of dinitrophenyl-amino acids as test samples, a series of experiments was performed with parameters such as the column length, sample volume, flow-rate, elution mode of the mobile phase and rotation speed. The highest efficiency, over 10,000 theoretical plates, was achieved with a 100 m long coiled tube and an 11 ml total capacity at a flow-rate of 0.01 ml/min at 800 rpm.

Amino Acids↗
PubMed1998

T lymphocyte activation signals for interleukin-2 production involve activation of MKK6-p38 and MKK7-SAPK/JNK signaling pathways sensitive to cyclosporin A.

p38/CSBP, a subgroup member of mitogen-activated protein kinase (MAPK) superfamily molecules, is known to be activated by proinflammatory cytokines and environmental stresses. We report here that p38 is specifically activated by signals that lead to interleukin-2 (IL-2) production in T lymphocytes. A p38 activator MKK6 was also markedly activated by the same stimulation. Pretreatment of cells with SB203580, a specific inhibitor of p38, as well as expression of a dominant-negative mutant of MKK6, suppressed the transcriptional activation of the IL-2 promoter. We also demonstrated that MKK7, a recently described MAPK kinase family member, plays a major role in the activation of stress-activated protein kinase (SAPK)/c-Jun NH2-terminal kinase (JNK) in T lymphocytes. Moreover, a dominant-negative mutant of MKK7 abrogated the transcriptional activation of the distal nuclear factor of activated T cells response element in the IL-2 promoter. Cyclosporin A, a potent immunosuppressant, inhibited activation of both p38 and SAPK/JNK pathways but not the MAPK/extracellular signal-regulated kinase (ERK) pathway. Our results indicate that both MKK6 to p38 and MKK7 to SAPK/JNK signaling pathways are activated in a cyclosporin A-sensitive manner and contribute to IL-2 gene expression in T lymphocytes.

Calcium-Calmodulin-Dependent Protein Kinases↗
PubMed1998

In vivo evidence that erythropoietin protects neurons from ischemic damage.

Erythropoietin (EPO) produced by the kidney and the liver (in fetuses) stimulates erythropoiesis. In the central nervous system, neurons express EPO receptor (EPOR) and astrocytes produce EPO. EPO has been shown to protect primary cultured neurons from N-methyl-D-aspartate (NMDA) receptor-mediated glutamate toxicity. Here we report in vivo evidence that EPO protects neurons against ischemia-induced cell death. Infusion of EPO into the lateral ventricles of gerbils prevented ischemia-induced learning disability and rescued hippocampal CA1 neurons from lethal ischemic damage. The neuroprotective action of exogenous EPO was also confirmed by counting synapses in the hippocampal CA1 region. Infusion of soluble EPOR (an extracellular domain capable of binding with the ligand) into animals given a mild ischemic treatment that did not produce neuronal damage, caused neuronal degeneration and impaired learning ability, whereas infusion of the heat-denatured soluble EPOR was not detrimental, demonstrating that the endogenous brain EPO is crucial for neuronal survival. The presence of EPO in neuron cultures did not repress a NMDA receptor-mediated increase in intracellular Ca2+, but rescued the neurons from NO-induced death. Taken together EPO may exert its neuroprotective effect by reducing the NO-mediated formation of free radicals or antagonizing their toxicity.

Animals↗
PubMed1998

A novel subtype of G-protein-coupled receptor kinase, GRK7, in teleost cone photoreceptors.

Two kinds of retinal cDNA fragments (OIGRK-R and -C) encoding the putative G-protein-coupled receptor kinases (GRKs) were isolated from medaka, Oryzias latipes. OIGRK-R appears to be closely related to the rhodopsin kinase (RK) found in the outer segments of mammalian photoreceptors, but the deduced amino acid sequence of OIGRK-C shows less than 50% identity to those of GRKs known to date, suggesting that OIGRK-C is a novel GRK subtype (GRK7). The mRNA of OIGRK-R is detectable in rods, and that of OIGRK-C is found in all four types of cone photoreceptor. The C-terminal of OIGRK-R has a consensus sequence for farnesylation, whereas, surprisingly, OIGRK-C has a consensus sequence for geranylgeranylation. Our result are consistent with the concept that lower vertebrates have rod- and cone-specific opsin kinases.

Amino Acid Sequence↗
PubMed1998

Homozygous deletion and frequent allelic loss of the 21q11.1-q21.1 region including the ANA gene in human lung carcinoma.

The frequent occurrence of 21q deletions in human non-small cell lung carcinoma (NSCLC) indicates the presence of a tumor suppressor gene on this chromosome arm. Since the ANA (Abundant in Neuroepithelium Area) gene, a member of an antiproliferative gene family, was mapped to 21q11.2-q21.1, we searched for genetic alterations of the ANA gene in human lung cancers. The gene was homozygously deleted in a human NSCLC cell line, Ma17. The gene was mapped in the 0.33 Mb Not1 fragment at 21q21.1 of the Not1 restriction map for 21q. Loss of heterozygosity (LOH) at this locus was detected in 24/47 (51.1%) of NSCLC, and the frequency of LOH in brain metastases was significantly higher than that in stage I-II primary tumors (P = 0.018). These results suggested that the homozygously deleted region harbors a novel tumor suppressor gene involved in NSCLC progression. Since mutation of the ANA gene was not detected in other lung cancer cell lines and fresh lung tumors with LOH at this locus, it is unlikely that the ANA gene is a target gene inactivated by two mutational events in this chromosomal region. Physical mapping of the homozygously deleted region showed that the deletion had occurred interstitially at 21q11.1-q21.1 and the size of the deletion was estimated as being more than 3 Mb. Our mapping results will facilitate further efforts to identify a tumor suppressor gene on 21q.

Aged↗
PubMed1998

Neurons induce the activation of microglial cells in vitro.

Although microglial cells are well known to become activated in the pathological brain, mechanisms underlying the microglial activation are not fully understood. In the present study, with an aim to elucidate whether neurons are involved in the microglial activation, we compared the morphology and the superoxide anion (O2-)-generating activity of rat microglial cells in pure culture with those of cells cocultured with rat primary cortical neurons. Microglial cells in pure culture in serum-free Eagle's minimum essential medium on poly-L-lysine-coated coverslips displayed ramified morphology and suppressed activity of O2- generation. In contrast, microglial cells in neuron-microglia coculture under the same conditions as those for the pure culture displayed ameboid shape and upregulated activity of O2- generation. Electron microscopic observation revealed that microglial cells in coculture were more abundant in Golgi apparatus and secretory granules than those in pure culture and that some of microglial cells in the vicinity of neurites exhibited membrane specialization reminiscent of a junctional apparatus with high electron density between a microglial soma and a neurite. Microglial cells in coculture tended to tie neurites in bundles by extending processes. Medium conditioned by neurons significantly enhanced O2- generation by microglia, but microglial cells in contact with or in close apposition to cocultured neurons were much more intensely activated than those remote from the neurons. Furthermore, the membrane fraction of cortical neurons activated microglial cells, and this effect was abolished by treating the neuronal membrane with trypsin or neuraminidase. In conclusion, neuronal-microglial contact may be necessary to mediate microglial activation. The present findings suggest that the contact of microglia with damaged neurons in the brain is a plausible cause to activate microglia in the neuropathological processes.

Animals↗
PubMed1998

Difference in the mechanisms for compensating ischemic acidosis in diabetic rat hearts.

To elucidate the difference in the mechanisms for alkalization during ischemic acidosis between diabetic and non-diabetic hearts, intracellular pH (pHi) was measured by phosphorus-31 magnetic resonance spectroscopy. Diabetes was induced by the injection of streptozotocin. The accumulation of proton ion (DeltaH+) during 15 min global ischemia at 37 degreesC was calculated from pH i. There were no significant differences in DeltaH+ between diabetic (DM: 0. 54+/-0.03 micromol/l,n=6; mean+/-s.e.m.) and non-DM hearts (0.57+/-0.04, n=6), when perfused with bicarbonate buffer. However, perfusion with HEPES buffer revealed a significant increase of DeltaH+ in DM (0.85+/-0.07, n=5) compared with non-DM (0.61+/-0.06, n=5P<0.05). On the contrary, the addition of a Na+/H+ exchange inhibitor (EIPA; 1 micromol/l) to bicarbonate buffer significantly increased DeltaH+ in non-DM (1.09+/-0.10, n=4) compared with DM (0.71+/-0.03, n=5P<0.01). Perfusion with HEPES buffer and EIPA equally increased DeltaH+ in both groups (DM 1.13+/-0.13, n=4; non-DM 1.15+/-0.14, n=4). Thus, the activity of Na+/H+ exchanger during ischemic acidosis, assessed as the increase of DeltaH+ induced by addition of EIPA to bicarbonate buffer, was higher in non-DM (0.52) than DM (0.17). In contrast, the contribution of bicarbonate-dependent systems evaluated by the deference of DeltaH+ between the bicarbonate buffer and the HEPES buffer was markedly bigger in DM (0.31) than non-DM (0.04). These results indicate that Na+/H+ exchange is a major mechanism to compensate ischemic acidosis in non-DM hearts, whereas bicarbonate-dependent systems compensate the depressed activity of Na+/H+ exchange in DM.

Acidosis↗