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K Matsuno

Publications and source records attributed to K Matsuno.

At least 73 records · Page 4Linked to original sources
PubMed1999

Functional evaluation of myocardial viability by 99mTc tetrofosmin gated SPECT--a quantitative comparison with 18F fluorodeoxyglucose positron emission CT (18F FDG PET).

UNLABELLED: To validate functional analysis of gated SPECT in detecting myocardial viability, seventeen patients (male 15, female 2, mean age 58) with angiographically proven chronic ischemic heart disease (RCA 6, LAD 10, LCX 1) and eight normal volunteers (all male) were studied. All patients underwent 18F FDG PET and 99mTc tetrofosmin (TF) gated SPECT within a week. After being displayed in a polar map, myocardial perfusion was regionally determined by the mean count in 9 segments at end diastole (ED) and end systole (ES) in gated SPECT. Systolic function was determined by the count increase ratio from ED to ES (WTI: ES - ED/ED). Glucose metabolism was assessed by 18F FDG PET in the segments correspondent to those defined for SPECT. TF %uptake of < 60% was defined as hypoperfusion, and FDG %uptake of < 50% was defined as reduced glucose metabolism. RESULTS: The myocardial segments were classified into 3 categories: "normal" perfusion (n = 85), "mismatch" (reduced perfusion with reserved FDG uptake, n = 25) and "matched" reduced perfusion and metabolic reduction (n = 26). Mean WTI in "mismatch" segment was 0.38 +/- 0.21, and was significantly greater than that in "matched reduced" segments, 0.15 +/- 0.20 (p < 0.001). It was also greater than that in "normal" segments, 0.27 +/- 0.16. Regression analysis showed that association between WTI and FDG %uptake was significant (r = 0.57, p < 0.0005) for the ischemic segments ("mismatch" + "matched", n = 51), but the association was weak for the entire segments although it was statistically significant (r = 0.26, p = 0.02, n = 136). CONCLUSION: For the segments determined as infarct by perfusion image, systolic functional analysis by gated SPECT is helpful in differentiation of a viable myocardial region or artifact from a scar. Nevertheless, further clinical and technical assessment is required for ECG gating to eliminate overestimation of viability and to warrant clinical use.

Adult↗
PubMed1999

Possible involvement of a sigma receptor subtype in the neck dystonia in rats.

To clarify which subtype of sigma receptors is involved in the sigma receptor-mediated neck dystonia in rats, we examined whether 1-(3,4-dimethoxyphenethyl)-4-(3-phenylpropyl)piperazine dihydrochloride (SA4503), a selective sigma1 receptor agonist, and 1,3-di-(2-tolyl)guanidine (DTG), a sigma1 and sigma2 receptor agonist, induce neck dystonia in rats. Microinjection of SA4503 into the red nucleus of rat brain scarcely produced neck dystonia at the concentration of 10 nmol/0.5 microl. On the contrary, DTG produced significant dystonia at a concentrations of more than 5 nmol/0.5 microl. These results indicate that the sigma2 receptor subtype, but not sigma1 receptor subtype, may play an important role in the sigma receptor-mediated neck dystonia in rats.

Animals↗
PubMed1999

Quantum mechanics in the present progressive mode and its significance in biological information processing.

Quantum mechanics practiced in the present progressive mode can incorporate into itself the propagation of a signal of a local character. It is possible to view that any movement in the present progressive mode is mutli-agential in the sense of internal interactions due to the absence of an external agency coordinating the global situation simultaneously. The idea of living memory is discussed as carrying the leftover from those actions completed and registered in the present perfect mode and surviving at any present moment. The occurrence of both the signal propagation of a local character and living memory is upheld upon exchange interaction of a quantum mechanical origin. Empirical evidence suggesting the likelihood of such an exchange interaction is found in the neurotransmitter-gated ion channels located on the plasma membrane of the muscle cell in the vicinity of secretory vesicles containing acetylcholine near the nerve terminal. Another case from the empirical evidence is seen in the actomyosin system demonstrating the unidirectional propagation of variations in the acceleration of the displacement of an actin filament sliding on myosin molecules in the presence of ATP molecules.

Actomyosin↗
PubMed1999

Intracellular signalling proteins as smart' agents in parallel distributed processes.

In eucaryotic organisms, responses to external signals are mediated by a repertoire of intracellular signalling pathways that ultimately bring about the activation/inactivation of protein kinases and/or protein phosphatases. Until relatively recently, little thought had been given to the intracellular distribution of the components of these signalling pathways. However, experimental evidence from a diverse range of organisms indicates that rather than being freely distributed, many of the protein components of signalling cascades show a significant degree of spatial organisation. Here, we briefly review the roles of 'anchor' 'scaffold' and 'adaptor' proteins in the organisation and functioning of intracellular signalling pathways. We then consider some of the parallel distributed processing capacities of these adaptive systems. We focus on signalling proteins-both as individual 'devices' (agents) and as 'networks' (ecologies) of parallel processes. Signalling proteins are described as 'smart thermodynamic machines' which satisfy 'gluing' (functorial) roles in the information economy of the cell. This combines two information-processing views of signalling proteins. Individually, they show 'cognitive' capacities and collectively they integrate (cohere) cellular processes. We exploit these views by drawing comparisons between signalling proteins and verbs. This text/dialogical metaphor also helps refine our view of signalling proteins as context-sensitive information processing agents.

Models, Biological↗
PubMed1999

Cell motility as an entangled quantum coherence.

Cell motility underlying muscle contraction is imputed to a macroscopic quantum mechanical coherence actualized locally in the body of a biological organism. Actin-activated myosin ATPase activity functions as a heat sink operating effectively at an extremely low temperature. Extraction of heat energy from the actin filament can help condensing the atomic degrees of freedom constituting the filament into a macroscopic quantum state carrying a nonvanishing linear momentum. Sliding movement of an actin filament on myosin molecules while hydrolyzing ATP molecules is a consequence of the quantum mechanical coherence due to an extremely slow release of energy stored in an ATP molecule.

Actins↗
PubMed1999

Thermodynamics in the present progressive mode and its role in the context of the origin of life.

The origin and evolution of biological organizations proceeding on Earth are put in a nonequilibrium thermodynamic framework within a cosmological context. The dynamic process responsible for chemical evolution leading to the origin of biological being depends upon consumer-dominating thermodynamics, in which the heat sink is taken to be active in extracting heat energy from a body at a higher temperature. Consumer-dominating thermodynamics follows from the fact that when a small hot body contacts a cold heat sink, it decreases the temperature at the possible fastest rate. The fastest temperature drop, when applied to chemical products being synthesized through the energy supplied from an external heat source, is selective in keeping only those products that can decrease the temperature at the fastest rate among the available alternatives. Synthesis of small organic molecules in the small ice grains in interstellar diffuse clouds irradiated by ultraviolet radiation is a representative case of consumer-dominating thermodynamics, in which diffuse clouds serve as cold heat sinks in the cosmological context. Another case of consumer-dominating thermodynamics predominant on Earth especially in the perspective of the origin and evolution of life is with submarine hydrothermal vents, in which the surrounding cold seawater constantly serves as the cold heat sink.

Biological Evolution↗
PubMed1999

Synthesis and in vivo evaluation of [11C]SA6298 as a PET sigma1 receptor ligand.

The potential of a 11C-labeled selective sigma1 receptor ligand, 1-(3,4-dimethoxyphenethyl)-4-[3-(3,4-dichlorophenyl)propyl]piperazine ([11C]SA6298), was evaluated as a positron emission tomography (PET) ligand for mapping sigma, receptors in the central nervous system and peripheral organs. [11C]SA6298 was synthesized by methylation of the desmethyl SA6298 with [11C]CH3I, with the decay-corrected radiochemical yield of 39 +/- 5% based on [11C]CH3I and with the specific activity of 53 +/- 17 TBq/mmol within 20 min from end of bombardment (EOB). In mice, the uptake of [11C]SA6298 was significantly decreased by carrier loading in the brain, liver, spleen, heart, lung, small intestine, and kidney in which sigma receptors are present as well as in the skeletal muscle. Pretreatment with SA6298 also blocked the uptake of [11C]SA6298 by these organs except for the small intestine, but significant displacement of [11C]SA6298 by posttreatment with SA6298 was observed only in the heart, lung, and muscle. In the blocking study with one of the eight sigma receptor ligands, including haloperidol, SA6298, NE-100, (+)-pentazocine, SA4503, (-)-pentazocine, (+)-3-PPP, and (+)-SKF 10,047 (in the order of the affinity for sigma1 receptor subtype), only SA6298 and an analog SA4503 significantly reduced the brain uptake of [11C]SA6298 to approximately 80% of the control, but the other six ligands did not. Peripherally, the uptake of [11C]SA6298 by the organs described above was decreased predominantly by SA6298 or SA4503, but the blocking effects of the other five ligands except for NE-100 depended on their affinity for sigma1 receptors. The saturable brain uptake of [11C]SA6298, approximately 20%, was also observed by tissue dissection method in rats and by PET in a cat. Ex vivo autoradiography of the rat brain showed a high uptake in the cortex and thalamus. In the cat brain a relatively high uptake was found in the cortex, thalamus, striatum, and cerebellum. These results have indicated a receptor-mediated uptake of the tracer to some extent in the brain and peripheral organs. However, the tracer has a limited potential for the PET study of the brain receptors because of a relatively high nonspecific binding.

Animals↗
PubMed1999

Control of the cell death pathway by Dapaf-1, a Drosophila Apaf-1/CED-4-related caspase activator.

We identified a Drosophila Apaf-1/CED-4 homolog gene, dapaf-1. Alternative splicing results in two dapaf-1 mRNA species, which encode distinct forms of caspase activator, Dapaf-1L (Apaf-1 type) and Dapaf-1S (CED-4 type). Distinct caspases were activated by these Dapaf-1 isoforms. Loss of Dapaf-1 function resulted in defective cytochrome c-dependent caspase activities and reduced apoptosis in embryo and in larval brain. Dapaf-1 activities were also involved in cell death induced by ectopic expression of reaper in the compound eye. These data suggest that Dapaf-1/cytochrome c-dependent cell death-inducing machinery is present in Drosophila, and the requirement of Dapaf-1/Apaf-1 in neural cell death is conserved through evolution.

Alternative Splicing↗
PubMed1999

Autocatalytic synthesis of oligoglycine in a simulated submarine hydrothermal system.

A flow reactor simulating a submarine hydrothermal system was constructed for examining the likelihood of oligopeptide synthesis from amino acids alone without recourse to any of condensing agents, templates or metallic ions. We demonstrated that when the initial reactant is glycine, the flow reactor can synthesize both di- and tri-glycine. The initial buildup of the yields of both the oligopeptides was found to be exponential with the elapse of time. The oligopeptide synthesis from glycine in the flow reactor could be autocatalytic.

Catalysis↗
PubMed1999

Metabolic imbalance and sporulation in an isocitrate dehydrogenase mutant of Bacillus subtilis.

A Bacillus subtilis mutant with a deletion in the citC gene, encoding isocitrate dehydrogenase, the third enzyme of the tricarboxylic acid branch of the Krebs cycle, exhibited reduced growth yield in broth medium and had greatly reduced ability to sporulate compared to the wild type due to a block at stage I, i.e., a failure to form the polar division septum. In early stationary phase, mutant cells accumulated intracellular and extracellular concentrations of citrate and isocitrate that were at least 15-fold higher than in wild-type cells. The growth and sporulation defects of the mutant could be partially bypassed by deletion of the major citrate synthase gene (citZ), by raising the pH of the medium, or by supplementation of the medium with certain divalent cations, suggesting that abnormal accumulation of citrate affects survival of stationary-phase cells and sporulation by lowering extracellular pH and chelating metal ions. While these genetic and environmental alterations were not sufficient to allow the majority of the mutant cell population to pass the stage I block (lack of asymmetric septum formation), introduction of the sof-1 mutant form of the Spo0A transcription factor, when coupled with a reduction in citrate synthesis, restored sporulation gene expression and spore formation nearly to wild-type levels. Thus, the primary factor inhibiting sporulation in a citC mutant is abnormally high accumulation of citrate, but relief of this metabolic defect is not by itself sufficient to restore competence for sporulation.

Adenosine Triphosphate↗
PubMed1999

Role of SpoVG in asymmetric septation in Bacillus subtilis.

Deletion of the citC gene, coding for isocitrate dehydrogenase, arrests sporulation of Bacillus subtilis at stage I after bipolar localization of the cell division protein FtsZ but before formation of the asymmetric septum. A spontaneous extragenic suppressor mutation that overcame the stage I block was found to map within the spoVG gene. The suppressing mutation and other spoVG loss-of-function mutations enabled citC mutant cells to form asymmetric septa and to activate the forespore-specific sigma factor sigmaF. However, little induction of mother cell-specific, sigmaE-dependent sporulation genes was observed in a citC spoVG double mutant, indicating that there is an additional defect(s) in compartmentalized gene expression in the citC mutant. These other defects could be partially overcome by reducing the synthesis of citrate, by buffering the medium, or by adding excess MnCl2. Overexpression of the spoVG gene in wild-type cells significantly delayed sigmaF activation. Increased expression and stability of SpoVG in citC mutant cells may contribute to the citC mutant phenotype. Inactivation of the spoVG gene caused a population of otherwise wild-type cells to produce a small number of minicells during growth and caused sporulating cells to complete asymmetric septation more rapidly than normal. Unlike the case for inactivation of the cell division inhibitor gene minD, many of these minicells contained DNA and appeared only when the primary sporulation signal transduction pathway, the Spo0A phosphorelay, was active. These results suggest that SpoVG interferes with or is a negative regulator of the pathway leading to asymmetric septation.

Bacillus subtilis↗
PubMed1999

[Anti-amnesic effects of sigma (sigma)-receptor agonists].

Both traditional and novel sigma (sigma)-receptor agonists have been reported to possess anti-amnesic effects in rodents. In particular, the anti-amnesic effects induced by the novel sigma1-receptor agonists, such as (+)-pentazocine, SA4503 and PRE-084, were shown in beta amyloid-peptide-induced, basal forebrain (BF)-lesioned and carbon monoxide (CO)-induced amnesia models and senescence-accelerated mouse (SAM). In addition, these sigma1-receptor agonists have good profiles for the central acetylcholine and dopamine systems. Moreover, they also have neuroprotective and anti-depressive effects. These evidence suggested that the sigma1-receptor agonists may be promising compounds for the treatment of dementing disorders such as Alzheimer's disease, senile dementia and vascular dementia. However, the sigma-receptor family is still considered to be enigmatic molecular targets. More molecular cloning and biochemical studies on the sigma-receptor family are needed.

Acetylcholine↗
PubMed1999

[A study of air pollution in the smoking hall].

We investigated the air pollution in the student smoking hall from February 1st in the winter season, and during 8 days in the middle of April in the spring season. The student smoking hall was in an open, draught location. Moreover, the concentration of pollutants were measured in three time periods: break, lecture and lunch times. The pollutants measured were nitrogen monoxide (NO), nitrogen dioxide (NO2), carbon monoxide (CO), carbon dioxide (CO2), suspended particulate matter (SPM) and polynuclear aromatic hydrocarbon (PAH). The concentrations of pollutants measured during the break times were of a relatively higher level than those during the lecture and lunch times. However, the concentration of pollutants were not influenced by ventilation operation in the smoking hall, which is not a closed place. SPM and CO2 concentrations during the break time were instantaneously investigated above Building Sanitation Standards Management, Japan (SPM: 0.15 mg/m3, CO2: 1,000 ppm). Especially, the SPM concentration was recognized to be strongly influenced by tobacco smoke.

Air Pollution, Indoor↗
PubMed1999

[Remaining solvents in dry cleaned over clothes].

We examined remaining solvents in dry cleaned trousers to estimate the magnitude of environmental pollution. A cleaning solvent of petroleum hydrocarbon was analyzed by means of capillary column mass spectrum gas chromatography. Principal ingredients were identified to be nonane, decane and undecane. The same main components were detected in dry cleaned trousers. Total amounts of evaporated vapor from a pair of trousers (480 g) in 5 days after dry cleaning were nonane (0.73 mg), decane (1.53 mg) and undecane (1.09 mg). The levels on the fifth day were 5%(nonane), 18%(decane) and 32%(undecane) of the first day's concentration, respectively. The half times of the remaining solvents were 1.0 day (nonane), 1.7 days (decane) and 2.7 days (undecane), respectively.

Clothing↗
PubMed1999

[Precision and accuracy of white blood cell differentiation by an automated blood cell analyzer].

Precision and accuracy are important to assure the quality of clinical laboratory tests. We investigated the precision and accuracy of white blood cell (WBC) differentiation by automated blood cell analyzers. The coefficients of variation (CVs) of neutrophil, lymphocyte, monocyte, eosinophil and basophil differentiation by GEN.S (Coulter), based on a flow system and VCS technology, were 1.1%, 1.5%, 4.6%, 2.1%, and 33.3%, respectively. Between-run precision for neutrophil, lymphocyte, monocyte, eosinophil and basophil differentiation by GEN.S using cell control, 5C in 26 serial days was 2.0%, 2.8%, 6.5%, 9.2%, and 29.5%, respectively. The precision of WBC differentiation by blood cell analyzers based on the flow system was excellent except for basophil. We studied the accuracy of WBC differentiation by blood cell analyzers based on the flow system in contrast with eye-count. The correlations between neutrophil, lymphocyte, monocyte, eosinophil, and basophil percentages counted by GEN.S and by eye-count were r = 0.968, 0.971, 0.902, 0.940, and 0.391, respectively. The agreement rate between WBC differentiation by Microx, a blood cell analyzer based on pattern recognition, and eye-count cell by cell was good except for basophils. The accuracy of WBC differentiation by blood cell analyzers was also excellent excluding basophils.

Humans↗
PubMed1999

[Iron].

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Female↗