Synthesis of superoxide dismutase derivative that specifically accumulates in renal proximal tubule cells

Protection of tissues from oxygen toxicity is one of the major prerequisites to aerobic life. Since a wide variety of xenobiotics with prooxidant activity is excreted by the kidney, renal tubule cells should be protected from hazardous oxygen species. Because intravenously injected Cu/Zn-type superoxide dismutase (SOD) is rapidly excreted in the urine in its intact form, effective dismutation of superoxide radicals cannot be achieved in vivo by intravenously administered SOD. To scavenge superoxide radicals and inhibit their toxic effects in and around renal tubule cells, a hexamethylene-diamine (AH)-conjugated SOD (AH-SOD) was synthesized. When injected intravenously into the rat, (125)I-labeled AH-SOD disappeared from the circulation with a half-life of 3 min and accumulated in the kidney. After 30 min of administration, more than 80% of the radioactivity derived from AH-SOD was found to localize in the kidney without being excreted in the urine. Immunohistochemical examination revealed that, 60 min after administration, the major part of AH-SOD localized in renal proximal tubule cells. Kinetic analysis using right-side-out-oriented renal brush border vesicles revealed that AH-SOD bound to their membrane surface by some mechanism which was inhibited by AH but not by heparin and albumin. These results indicated that AH-SOD rapidly underwent renal glomerular filtration, bound to apical plasma membranes of proximal tubule cells, and localized in these cells for a fairly long time without being excreted in the urine. Thus, AH-SOD might permit studies on the role of superoxide radicals in and around renal proximal tubule cells.

Contractile and protractile coordination within an actin filament sliding on myosin molecules

An actin filament exhibits distortions longitudinally when it slides upon myosin molecules. We observed that the actin filament demonstrated contractile distortions at low ATP concentrations and protractile distortions at high concentrations. Temporal development of such distortions was identified, by tracing each of several speckled fluorescent markers attached to the actin filament. Close association of the sliding movement to the moving distortions of an actin filament suggests the presence of a unitary mechanism regulating the apparently two different modes of dynamic movement.

Acute and chronic administration of the selective sigma1 receptor agonist SA4503 significantly alters the activity of midbrain dopamine neurons in rats: An in vivo electrophysiological study

In this study, we examined the effect of the acute and repeated administration of the selective sigma (sigma)1 receptor agonist 1-(3, 4-dimethoxyphenethyl)-4-(3-phenylpropyl)piperazine dihydrochloride (SA4503) on the number and firing pattern of spontaneously active dopamine (DA) neurons in substantia nigra pars compacta (SNC) and ventral tegmental area (VTA) in anesthetized, male Sprague-Dawley rats. This was accomplished using the technique of in vivo extracellular single unit recording. The intravenous administration of SA4503 (0.01-1.28 mg/kg) did not significantly alter the firing rate or pattern of spontaneously active DA neurons in either the SNC or VTA. A single injection of either 0.1 or 0.3 mg/kg i.p. of SA4503 did not alter the number of spontaneously active SNC and VTA DA neurons. In contrast, a single injection of 1 mg/kg i.p. of SA4503 produced a significant decrease and increase in the number of spontaneously active SNC and VTA DA neurons, respectively. Overall, the firing pattern parameters of spontaneously active SNC DA neurons were altered more significantly than those of spontaneously active VTA DA neurons following the acute administration of SA4503. The repeated administration (one injection per day for 21 days) of 0.3 and 1 mg/kg i.p. of SA4503 produced a significant increase in the number of spontaneously active VTA DA neurons. In addition, the repeated administration of SA4503 produced a greater alteration of the firing pattern of spontaneously active VTA compared to SNC DA neurons. Our results suggest that the administration of SA4503 significantly alters the activity of spontaneously active midbrain DA neurons, particularly those in the VTA following repeated administration.

Association of matrilysin expression with recurrence and poor prognosis in human esophageal squamous cell carcinoma

Matrix metalloproteinase-7 (matrilysin) has been implicated in tumor invasion and metastasis as well as tumor initiation and growth. In this study, we analyzed an association between immunohistochemically detected matrilysin expression at the invasive front in esophageal squamous cell carcinomas and clinicopathological characteristics and determined whether matrilysin predicts recurrence and/or survival Matrilysin expression at the invasive front was detected in 49% of 100 carcinoma tissues and was associated with the depth of invasion (P < 0.0001), advanced tumor stage (P = 0.0159), recurrences (P = 0.0002), and recurrences within the first postoperative year (P = 0.002). Patients with matrilysin-positive carcinoma had a significantly shorter disease-free and overall survival time than did those with a matrilysin-negative one (P < 0.0001). Matrilysin remained a significant predictive value for disease-free and overall survival in multivariate analysis, including conventional clinicopathological factors (P = 0.0007 and 0.0004, respectively). Our results suggest that matrilysin may play a key role in the progression of esophageal carcinoma and that its detection may be useful for the prediction of recurrence and poor prognosis and, possibly, for selecting patients for anti-matrix metalloproteinase therapy.

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.

[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.

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.

Selective coupling of mouse brain metabotropic sigma receptor with recombinant Gi1

Various sigma (sigma) ligands including (+)-pentazocine stimulated [35S]GTPgammaS binding in synaptic membranes from the mouse cerebellum. The (+)-pentazocine-stimulated [35S]GTPgammaS binding was blocked by the treatment of membranes with pertussis toxin (PTX), but completely recovered by the reconstitution of PTX-treated membranes with recombinant Gi1, but not with GoA. These findings suggest that metabotropic sigma receptors are selectively coupled to Gi1 protein.

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

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.

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.

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.

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.

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.

Presentation of tumor antigens by phagocytic dendritic cell clusters generated from human CD34+ hematopoietic progenitor cells: induction of autologous cytotoxic T lymphocytes against leukemic cells in acute myelogenous leukemia patients

The use of antigen-presenting dendritic cells (DCs) is currently proposed for tumor immunotherapy through generation of CTLs to tumor antigens in cancer patients. In this study, DCs were differentiated using granulocyte-macrophage colony-stimulating factor and tumor necrosis factor-alpha from CD34+ hematopoietic progenitor cells that had been mobilized into the peripheral blood. To use the phagocytic activity of DCs for processing and presentation of tumor antigens, we established DC clusters containing immature DCs by preserving proliferating cell clusters without mechanical disruption. After an 11-day culture, the developed clusters contained not only typical mature DCs but also immature DCs that showed active phagocytosis of latex particles, suggesting that the clusters consisted of DCs of different maturational stages. These heterogeneous clusters could present an exogenous protein antigen, keyhold limpet hemocyanin, to both CD4+ and CD8+ T lymphocytes. Furthermore, in three acute myelogeneous leukemia patients, clusters pulsed with autologous irradiated leukemic cells could also induce antileukemic CTLs. The mechanical disruption of clusters abrogated the induction of CTLs to leukemic cells as well as to hemocyanin. This observation gives an important information for the use of heterogeneous DC clusters derived from autologous peripheral blood CD34+ cells in the case of immunotherapy for leukemia.

[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.

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.

[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.

Elongation of oligopeptides in a simulated submarine hydrothermal system

Oligomerization of a peptide was attempted in a flow reactor that simulated a submarine hydrothermal system. When fluid containing glycine repeatedly circulated through the hot and cold regions in the reactor, oligopeptides were made from glycine. When divalent ions (such as copper ions) were added under acidic conditions, oligoglycine was elongated up to hexaglycine. This observation suggests that prebiotic monomers could have oligomerized in the vicinity of submarine hydrothermal vents on primitive Earth.

[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.

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.